mid-14c., condicioun, "particular mode of being of a person or thing," also "a requisite or prerequisite, a stipulation," from Old French condicion "stipulation; state; behavior; social status" (12c., Modern French condition), from Medieval Latin conditionem (nominative conditio), properly condicio "agreement; stipulation; the external position, situation, rank, place, circumstances" of persons, "situation, condition, nature, manner" of things, from condicere "to speak with, talk together, agree upon," in Late Latin "consent, assent," from assimilated form of com "together" (see con-) + dicere "to speak" (from PIE root *deik- "to show," also "pronounce solemnly").
Classical Latin condicio was confused in Late Latin with conditio "a making," from conditus, past participle of condere "to put together." The sense evolution in Latin apparently was from "stipulation" to "situation, mode of being."
Meaning "rank or state with respect to ordered society" is from late 14c. in English. From the notion of "prerequisite" comes the sense of "a restricting or limiting circumstance" (late 14c.). Also in Middle English "personal character, disposition" (mid-14c.).
late 15c., "to make conditions, stipulate," from condition (n.). Meaning "subject to something as a condition" is from 1520s; sense of "form a prerequisite of" is from 1868. Meaning "to bring to a desired condition" is from 1844; psychological sense of "teach or accustom (a person or animal) to certain habits or responses" is from 1909. Related: Conditioned; conditioning.
c. 1600, "a bargainer," agent noun from condition (v.). Meaning "an agent that brings something into good condition" is from 1888; since c. 1960 usually in reference to hair care products. Before that, it often was short for air conditioner(1938).
late 14c., condicionel, "depending on a condition or circumstance, contingent," from Old French condicionel (Modern French conditionnel), from Late Latin conditionalis, from Latin condicionem "agreement; situation" (see condition (n.)). Related: Conditionally; conditionality.
It forms all or part of: abdicate; abdication; addict; adjudge; apodictic; avenge; benediction; betoken; condition; contradict; contradiction; dedicate; deictic; deixis; dictate; diction; dictionary; dictum; digit; disk; ditto; ditty; edict; Eurydice; index; indicate; indication; indict; indiction; indictive; indite; interdict; judge; judicial; juridical; jurisdiction; malediction; malison; paradigm; policy (n.2) "written insurance agreement;" preach; predicament; predicate; predict; prejudice; revenge; soi-disant; syndic; teach; tetchy; theodicy; toe; token; valediction; vendetta; verdict; veridical; vindicate; vindication; voir dire.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit dic- "point out, show;" Greek deiknynai "to show, to prove," dike "custom, usage;" Latin dicere "speak, tell, say," digitus "finger," Old High German zeigon, German zeigen "to show," Old English teon "to accuse," tæcan "to teach."