(1):

(v. i.) To play with anything; hence, to be busy about trifles.

(2):

(v. t.) To touch lightly, or play with; to tweedle; to twirl; as, to twiddle one's thumbs; to twiddle a watch key.

(3):

(n.) A slight twist with the fingers.

(4):

(n.) A pimple.