Other forms: tickling, tickled, tickles
To tickle is to touch somebody lightly so that they laugh. Tickle his feet, stop tickling, ticklish.
You cannot tickle yourself, because the brain predicts your own touch and cancels the sensation — which is one of the more reliable facts in neuroscience. It also means to cause a light itching feeling: the wool tickles. And it means to amuse: it tickled me, tickled pink, meaning delighted. Note ticklish, which describes both a person who is easily tickled and a situation that needs careful handling.
1verbtickleTo touch somebody lightly so as to cause laughter.
“Dad tickled the baby's feet until she giggled.”
2verbamuseTo amuse somebody.
“The whole idea tickled her enormously.”
tickle is a light touching.
Middle English tiklen is probably a frequentative of tick, meaning to touch lightly — the repeated small touch is built into the word's shape, as it is in sparkle and crackle.
Middle English
tiklen
English, today
tickle
From Middle English tiklen, tikelen, of unknown origin. Perhaps from a frequentative form of Middle English tikken (“to touch lightly”), thus equivalent to tick + le; or perhaps related to Old English tinclian (“to tickle”). Compare frr tigele (“to tickle”) (Hallig dialect), and tiikle (“to tickle”) (Amrum dialect), German dialectal zicklen (“to excite; stir up”). Alternatively, from a metathetic alteration of Middle English kitelen "to tickle"; see kittle. Both are ultimately.
Etymology from Wiktionary, CC BY-SA