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.
