Etymology

From Old French catellier ‎(“to excite, cause tremors”) (compare French chatouiller), from Medieval Latin catilō, catilāre ‎(“tickle”, verb), from Frankish *kitilōn ‎(“to tickle”), from Proto-Germanic *kitilōną, frequentative of *kitōną ‎(“to tickle”), from Proto-Indo-European *geid- ‎(“to stick, jab, tickle”).