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- (source also of Middle Dutch kallen "speak, say, tell," Dutch kallen "to talk, chatter," Old High German kallon "speak loudly, call"), 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 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. To call it a night "go to bed" is from 1919.

perfective prefix, in yclept, etc.; a deliberate archaism, introduced by Spenser and his imitators, representing an authentic Middle English prefix y-, earlier i-, from Old English ge-, originally meaning "with, together" but later a completive or perfective element, 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 (such as alike, aware, handiwork).

Among hundreds of Middle English words it formed are yfallen, yhacked ("completely hacked," probably now again useful), yknow, ymarried, ywrought.