convenance (n.)

early 15c., (intransitive) "to come together, meet in the same place," usually for some public purpose, from Old French convenir "to come together; to suit, agree," from Latin 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."

Transitive sense of "call together, cause to assemble" is from 1590s. Related: Convened; convener; convening.