At the point of death or in terminal decline; in a state where normal activity has effectively ceased and recovery is unlikely; dying, though not yet technically dead

Moribund is the most dramatic word in this set — it sits at the threshold between life and death, describing the state where a thing still technically exists but has effectively ceased to function. The word comes from the Latin moribundus (dying), and that clinical precision is still present: something moribund has not yet died, but it is dying, and the distinction between its current state and death is one of form rather than substance. A moribund industry still has some companies operating in it, but investment has dried up, talent has moved elsewhere, and the remaining activity is winding down rather than sustaining. A moribund institution still has staff and premises, but its core activities have ceased and its purpose has effectively lapsed. The word often implies that the formal declaration of death — the dissolution, the closure, the official end — is a matter of administrative timing rather than of real significance.

Where you’ll encounter it: Economic commentary, institutional analysis, political writing, descriptions of industries, organisations, movements, and practices that are failing or have effectively failed

“By the time the government finally announced the closure of the programme, it had been moribund for years — its last meaningful output had come five years earlier, its core staff had long since dispersed to other positions, and the announcement was received less as news than as the belated official acknowledgement of a fact that everyone had accepted long before.”

No longer produced or used; having been superseded by something newer, more effective, or more appropriate; still potentially in existence but serving no useful purpose that a better alternative does not serve more effectively

Obsolete is ending through supersession — the specific, functional replacement that renders something unnecessary. Unlike moribund (where the thing is dying from within), something obsolete has been replaced from without: a new technology, a new practice, a new standard has arrived and does the job better, making the old thing redundant. The obsolete thing may still exist — there are still fax machines, there are still people who know how to operate them — but they serve no purpose that email does not serve more effectively. The word carries a note of decisiveness that antiquated lacks: to call something obsolete is to say not just that it is old but that it has been functionally replaced, that the case for continuing to use it has been definitively lost.

Where you’ll encounter it: Technology commentary, manufacturing and industry analysis, professional practice descriptions, legal and regulatory writing, linguistic analysis, economic commentary

“The legislation had been rendered obsolete by technological developments that its drafters could not have anticipated — the regulatory framework it established assumed a set of business practices that had simply ceased to exist, replaced by digital processes the Act had no mechanism to address.”

Old-fashioned or outdated; belonging to an earlier period and no longer appropriate or effective in the current context; left behind by the general passage of time and change rather than by a specific replacement

Antiquated is the word for what has been left behind by time without being specifically superseded. An antiquated system is one that was designed for a different era and has not been updated to match the changed circumstances it now operates in; an antiquated practice is one that made sense in an earlier context but is inappropriate or ineffective in the present one; an antiquated attitude is one that reflects assumptions that have been overtaken by social and cultural change. The word is consistently pejorative — to call something antiquated is to criticise it as unsuitable for the present, as belonging to a past that is no longer the relevant frame of reference. This distinguishes it slightly from archaic, which can be used more neutrally, and significantly from obsolete, which implies a specific replacement rather than a general falling-behind.

Where you’ll encounter it: Institutional and legal commentary, descriptions of professional practices and regulations, social and cultural criticism, editorial writing about organisations and systems that have not kept pace with change

“The employment tribunal ruled that the company’s disciplinary procedures were antiquated — reflecting a management philosophy from the 1970s that treated employees as subordinates to be managed rather than professionals to be engaged, and wholly at odds with current legal expectations of workplace fairness.”

Very old; belonging to an early or ancient historical period; no longer in ordinary use but still encountered in specialist, historical, or literary contexts; (of language) belonging to an earlier stage of a language’s development

Archaic reaches further back than antiquated — it describes not merely something old-fashioned but something that belongs to a genuinely ancient or remote historical period. Archaic laws are laws from the distant past; archaic language is language from an early period of a tongue’s development, still recognisable but no longer in everyday use; archaic art is art from the earliest periods of a civilisation’s artistic production. The word can be used with neutral or even positive connotations in some contexts — archaism in poetry is sometimes a deliberate stylistic choice, and archaic practices in religious or ceremonial contexts may be valued precisely because of their antiquity. This flexibility distinguishes archaic from antiquated, which is almost always pejorative. When archaic is used critically, it implies not just that something is old but that it belongs to a period so remote that its continued use reflects a fundamental disconnection from the present.

Where you’ll encounter it: Historical and linguistic writing, literary criticism, legal commentary (where archaic language persists), descriptions of ancient practices and beliefs, archaeology and classical studies

“The contract’s language was archaic to the point of opacity — drawing on legal formulations that had been standard in the seventeenth century but had since been replaced, in virtually every jurisdiction, by clearer modern equivalents that said the same thing in a fraction of the words.”

Worn out, weakened, or ruined by age and neglect; in a state of serious deterioration through long use, poor maintenance, or the accumulated damage of time; no longer capable of functioning as originally intended

Decrepit is the only word in this set that is primarily physical — it describes the condition of things that have been worn down and weakened by the passage of time and the accumulated neglect or damage that comes with it. A decrepit building is one whose structure has deteriorated to the point where it is no longer safe or functional; decrepit infrastructure is infrastructure that has not been maintained and is failing as a result; a decrepit organisation is one whose physical resources — premises, equipment, systems — have deteriorated to the point of undermining its function. The word carries a stronger sense of physical deterioration than the others: where moribund describes functional decline and obsolete describes supersession, decrepit describes the material wearing-away that comes with age and neglect. It is consistently critical — there is nothing neutral about calling something decrepit.

Where you’ll encounter it: Descriptions of buildings, infrastructure, and physical environments; commentary on ageing bodies and health; descriptions of institutions and organisations whose physical resources have deteriorated; travel and architectural writing

“The survey found that a third of the school buildings in the district were decrepit — with leaking roofs, failing heating systems, crumbling plasterwork, and structural issues that had been flagged in successive maintenance reports and repeatedly deferred for lack of funding.”