thrill (v.)youdaoicibaDictYouDict[thrill 词源字典]
early 14c., "to pierce, penetrate," metathesis of Old English þyrlian "to perforate, pierce," from þyrel "hole" (in Middle English, also "nostril"), from þurh "through" (compare Middle High German dürchel "pierced, perforated;" see through) + -el. Meaning "give a shivering, exciting feeling" is first recorded 1590s, via metaphoric notion of "pierce with emotion." Related: Thrilled; thrilling.[thrill etymology, thrill origin, 英语词源]
tickle (v.)youdaoicibaDictYouDict
early 14c. (intransitive) "to be thrilled or tingling," of uncertain origin, possibly a frequentative form of tick (v.) in its older sense of "to touch." The Old English form was tinclian. Some suggest a metathesis of kittle (Middle English kytyllen), from Dutch kietelen, from a common North Sea Germanic word for "to tickle" (compare Old Norse kitla, Old High German kizzilon, German kitzeln).

Meaning "to excite agreeably" (late 14c.) is a translation of Latin titillare. Meaning "to touch lightly so as to cause a peculiar and uneasy sensation in the nerves" is recorded from late 14c.; that of "to poke or touch so as to excite laughter" is from early 15c.; figurative sense of "to excite, amuse" is attested from 1680s. Related: Tickled; tickling. The noun is recorded from 1801. To tickle (one's) fancy is from 1640s.