Origin and history of yclept

"to call; to name" (archaic), from Old English cleopian, clipian "to speak, call; summon, invoke; implore," which is of uncertain origin.

mid-13c., "cry out; call for, summon, invoke; ask for, demand, order; give a name to, apply by way of designation," from Old Norse kalla "cry loudly, summon in a loud voice; name, call by name," from Proto-Germanic *kall-, from PIE root *gal- "to call, shout." Related: Called; calling.

Old English cognate ceallian "to shout, utter in a loud voice" was rare, the usual word being clipian (source of Middle English clepe, yclept). Old English also had hropan, hruofan, cognate of German rufen.

The "heads-or-tails" coin-toss sense is from 1801; the card-playing sense "demand that the hands be shown" is from 1670s; the specific poker sense of "match or raise a bet" is by 1889. The meaning "make a short stop or visit" (Middle English) was literally "stand at the door and call." The "attempt a telephone connection with" sense is from 1882.

To call up "summon" is from mid-15c. To call for "demand, require" is from 1530s (earlier in this sense was call after, c. 1400). To call (something) back "revoke" is from 1550s. To call (something) off "cancel" is by 1888; earlier call off meant "summon away, divert" (1630s). To call (someone) names is from 1590s. To call out someone to fight (1823) corresponds to French provoquer.

Germanic cognates include Middle Dutch kallen "speak, say, tell," Dutch kallen "to talk, chatter," Old High German kallon "speak loudly, call."

perfective prefix, a deliberate archaism reintroduced by Spenser and his imitators (yclept, yclad, etc.), representing an authentic Middle English prefix y-, earlier i-, from Old English ge-, originally meaning "with, together" but later a completive or perfective element.

This is from Proto-Germanic *ga- "together, with" (also a collective and intensive prefix), from PIE *kom "beside, near, by, with" (cognate with Sanskrit ja-, Latin com-, cum-; see com-). It is still living in German and Dutch ge-, and survives, disguised, in some English words (alike, aware, handiwork).

New coinages in it after c. 1300 mostly are past-participle adjectives; among hundreds in Middle English are yfallen, yhacked ("completely hacked," perhaps useful again 21c.), yknow, ymarried, ywrought.