Invalid

Part of speech: adjective, noun

Pronunciation: /ɪnˈvæl.ɪd/

Definitions

  1. Not conforming to established rules, standards, or correctness; lacking official or legal recognition or authorization; not meeting the conditions required for acceptance or use
  2. Failing to comply with prescribed criteria or regulations; legally or officially unrecognized; deemed unacceptable or void due to errors or nonconformity
  3. Exceeding or falling short of accepted standards or rules, thus void or rejected; without legal force, authority, or validity; characterized by improper or erroneous status

Etymology: The adjective and noun in question both trace back to Latin, but their journey into English reveals a subtle evolution in sense and usage. Arriving in the late 15th century, the term originally referred to something weak or feeble, especially in terms of health. It was borrowed from Latin "invalidus", meaning "weak" or "not strong", a compound of the prefix "in-" (not) and "validus" (strong, healthy, powerful). While "validus" became the ancestor of "valid", the prefix "in-" altered its sense to the negative. As the centuries passed, the word shifted from an adjective describing frailty to a noun referring to a person who is chronically ill or disabled. This nominal usage became especially common in the 18th and 19th centuries, often describing soldiers incapacitated by wounds or disease, and later more generally for anyone long-term sick. In recent decades, the noun has largely fallen out of favor in English due to its association with negative stereotypes, but the adjective persists in legal and technical contexts, where it means "not legally or factually sound". It is worth noting that there is a homograph—"invalid" pronounced differently (/ˈɪn.və.lɪd/)—which is the opposite of "valid" in logic and law. Despite the identical spelling, this "invalid" is a separate development, directly negating "valid" with the prefix "in-". Thus, the modern English word combines strands from Latin roots and semantic shifts, with both meanings coexisting but pronounced differently.

Synonyms: void, null, unfounded

Antonyms: valid, sound, legitimate