"incurved," early 15c., from Old French concave (14c.) or directly from Latin concavus "hollow, arched, vaulted, curved," from con-, here perhaps an intensive prefix (see con-), + cavus "hollow" (from PIE root *keue- "to swell," also "vault, hole").

"having a common center," c. 1400, from Old French concentrique, from Medieval Latin concentricus, from assimilated form of com "with, together" (see con-) + Latin centrum "circle, center" (see center (n.)).

"descended from a common ancestor," c. 1600, from French consanguin (14c.), from Latin consanguineus "of the same blood," from assimilated form of com "with, together" (see con-) + sanguineus "of blood" (see sanguinary).

"having the same limit, touching at the boundary," 1670s, from Latin conterminus "bordering upon, having a common boundary," from assimilated form of com "together, with" (see con-) + terminus "end, boundary line" (see terminus). Related: Conterminously; conterminousness.

"rolled up together," 1794, from Latin convolutus, past participle of convolvere "to roll together," from assimilated form of com "with, together" (see con-) + volvere "to roll," from PIE root *wel- (3) "to turn, revolve." The noun meaning "something convoluted" is from 1846.

"having the character of a conspecies, of the same species but with variations," 1837, from conspecies "a sub-species, a climatic or geographical variety of another" (1837), from con- "with" + specific, here serving as the adjective of species (n.). From 1962 as a noun.

"act of appropriating as forfeit," 1540s, from French confiscation, from Latin confiscationem (nominative confiscatio), noun of action from past-participle stem of confiscare, from assimilated form of com "with, together" (see con-) + fiscus "public treasury" (see fiscal).

early 15c., "a flowing together, especially of two or more streams," from Late Latin confluentia, from Latin confluentem (nominative confluens), present participle of confluere "to flow together," from assimilated form of com "with, together" (see con-) + fluere "to flow" (see fluent).

"pertaining to marriage," 1650s, from Latin connubialis, variant of conubialis "pertaining to wedlock," from conubium "marriage," from assimilated form of com "with, together" (see con-) + nubere "to wed" (see nuptial). Related: Connubially.

"causing constriction," c. 1600, from Latin constringentem (nominative constringens), present participle of constringere "to bind together, tie tightly, fetter, shackle, chain," from assimilated form of com "with, together" (see con-) + stringere "to draw tight" (see strain (v.)).