forensic (adj.)

mid-15c., "place of assembly in ancient Rome," from Latin forum "marketplace, open space, public place," apparently akin to foris, foras "out of doors, outside" (from PIE root *dhwer- "door, doorway"). The sense of "assembly, place for public discussion" is recorded by 1680s.

Middle English -ik, -ick, word-forming element making adjectives, "having to do with, having the nature of, being, made of, caused by, similar to," from French -ique and directly from Latin -icus or from cognate Greek -ikos "in the manner of; pertaining to." From PIE adjective suffix *-(i)ko, which also yielded Slavic -isku, adjectival suffix indicating origin, the source of the -sky (Russian -skii) in many surnames. In chemistry, indicating a higher valence than names in -ous (first in benzoic, 1791).

In Middle English and after often spelled -ick, -ike, -ique. Variant forms in -ick (critick, ethick) were common in early Modern English and survived in English dictionaries into early 19c. This spelling was supported by Johnson but opposed by Webster, who prevailed.

Proto-Indo-European root meaning "door, doorway." The base form is frequently in dual or plural, leading to speculation that houses of the original Indo-Europeans had doors with two swinging halves.

It forms all or part of: afforest; deforest; door; faubourg; foreclose; foreign; forensic; forest; forfeit; forum; hors d'oeuvre; thyroid.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit duárah "door, gate;" Old Persian duvara- "door;" Lithuanian dùrys (plural); Greek thyra "door;" Latin foris "out-of-doors, outside;" Gaulish doro "mouth;" Old Prussian dwaris "gate;" Russian dver' "a door;" Old English dor, German Tür "door," Gothic dauro "gate."