Available Definitions:
1) v. t. - To touch lightly, so as to produce a peculiar thrilling sensation, which commonly causes laughter, and a kind of spasm which become dengerous if too long protracted.
2) v. t. - To please; to gratify; to make joyous.
3) v. i. - To feel titillation.
4) v. i. - To excite the sensation of titillation.
5) a. - Ticklish; easily tickled.
6) a. - Liable to change; uncertain; inconstant.
7) a. - Wavering, or liable to waver and fall at the slightest touch; unstable; easily overthrown.