Convenient
late Middle English (in the sense ‘befitting, becoming, suitable’): from Latin convenient- ‘assembling, agreeing, fitting’, from the verb convenire (see convene).
wiktionary
From Middle English convenient, from Latin conveniens(“fit, suitable, convenient”), present participle of convenire(“to come together, suit”); see convene and compare covenant.
etymonline
convenient (adj.)
late 14c., "fit, suitable, proper; affording accommodation; opportune, favorable," from Latin convenientem (nominative conveniens), present participle of convenire "to come together, meet together, assemble; unite, join, combine; agree with, accord; be suitable or proper (to)," from assimilated form of com "with, together" (see con-) + venire "to come" (from a suffixed form of PIE root *gwa- "to go, come").
Meaning "personally suitable to ease of action or performance" is from late 15c. Sense of "at hand, easily accessible" (1849) is marked in OED as "Ireland and U.S."
