The tickle can be divided into two separate categories of sensation, knismesis and gargalesis. Knismesis, also known as a "moving itch", is a mildly annoying sensation caused by a light …

Gargalesis, or tickle, is one of the most trivial yet enigmatic human behaviors. We do not know how a touch becomes ticklish or why we respond to other people’s tickles but not our own.

The meaning of TICKLE is to touch (a body part, a person, etc.) lightly so as to excite the surface nerves and cause uneasiness, laughter, or spasmodic movements.

us / ˈtɪk·əl / an unpleasant feeling in your throat that might make you cough (Definition of tickle from the Cambridge Academic Content Dictionary © Cambridge University Press)

tick, tickle - Tick, as in "sound of a clock," "mark of correctness," originally meant "light touch, tap," and its modern senses are recent developments; tickle is probably a derivative of this version of tick.

to stroke lightly with the fingers, with a feather, etc., so as to cause a tingling or itching sensation in:[~ + object] To wake him up she would tickle his nose with a feather.

When you tickle someone, you move your fingers lightly over their body, often in order to make them laugh.