citation n.

mid-15c., "to summon, call upon officially," from Old French citer "to summon" (14c.), from Latin citare "to summon, urge, call; put in sudden motion, call forward; rouse, excite," frequentative of ciere "to move, set in motion, stir, rouse, call, invite" from PIE root *keie- "to set in motion, to move to and fro."

Sense of "call forth a passage of writing, quote the words of another" is first attested 1530s. Related: Cited; citing.

also keiə-, Proto-Indo-European root meaning "to set in motion."

It might form all or part of: behest; cinema; cinematography; citation; cite; excite; hest; hight; hyperkinetic; incite; kinase; kinematics; kinesics; kinesiology; kinesis; kinesthesia; kinesthetic; kinetic; kineto-; kino-; oscitant; recital; recitation; recite; resuscitate; solicit; solicitous; suscitate; telekinesis.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit cyavate "stirs himself, goes;" Greek kinein "to move, set in motion; change, stir up," kinymai "move myself;" Latin ciere (past participle citus, frequentative citare) "to set in motion, summon;" Gothic haitan "call, be called;" Old English hatan "command, call."