1570s, "consisting" (a sense now obsolete), from Latin consistentem (nominative consistens), present participle of consistere "to stand firm, take a standing position, stop, halt," from assimilated form of com "with, together" (see con-) + sistere "to place," causative of stare "to stand, be standing," from PIE root *sta- "to stand, make or be firm."
Sense of "standing together in agreement, agreeing" (with with) is first attested 1640s; meaning "marked by consistency" is from 1732. The literal, physical sense survives in consistency. Related: Consistently.
1590s, "to be consistent, to follow regularly in natural or logical order," from Latin cohaerere "to cleave together," in transferred use, "be coherent or consistent," from assimilated form of com "together" (see co-) + haerere "to adhere, stick" (see hesitation). More literal sense of "to stick, stick together, cleave" is from 1610s. Related: Cohered; cohering.
1550s, "harmonious;" 1570s, "sticking together," also "connected, consistent" (of speech, thought, etc.), from French cohérent (16c.), from Latin cohaerentem (nominative cohaerens), present participle of cohaerere "cohere," from assimilated form of com "together" (see co-) + haerere "to adhere, stick" (see hesitation).
mid-14c., reconcilen, transitive, in reference to persons, "to restore to union and friendship after estrangement or variance," also of God or Christ, "restore (mankind, sinners) to favor or grace," from Old French reconcilier (12c.) and directly from Latin reconcilare "to bring together again; regain; win over again, conciliate," from re- "again" (see re-) + conciliare "make friendly" (see conciliate).
Reflexive sense of "become reconciled, reconcile oneself" is from late 14c. Meaning "to make (discordant facts or statements) consistent, rid of apparent discrepancies" is from 1550s. Mental sense of "make (actions, facts, conditions, etc.) consistent with each other in one's mind" is from 1620s. Sense of "bring into acquiescence or quiet submission" (with to) is from c. 1600. Related: Reconciled; reconciling.