1. To irritate by a squeeze between the thumb and finger, to pinch, or to cause a twitch: After correcting so many student papers, Mrs. Black’s eye muscles were vellicating so much that she had to put down her pen and take a break!
2. To touch a part of the body lightly in order to excite the surface nerves and to cause uneasiness, laughter, or involuntary muscular jerks and contractions: Fred liked to vellicate his baby brother on the soles of his feet because it made tiny Tim giggle a lot!
3. Etymology: from Latin vellicatus, past participle of vellicare and vellere, "to pluck, to pull, to twitch", which is of uncertain origin.