(noun) The act of making an "L" shape with one's index finger placed between your eyebrows and thumb placed just above the upper lip in order to give the appearance of a protruding nose, a stereotypically common characteristic of a JEW. While never spoken, typing "Lface" in a chatroom is acceptable.
Upon passing a person with obvious Jewish traits, one might make an Lface, directed either at the accused (overtly) or one's present company (covertly).
Ira: Let's eat before we go. Bar food is so over-priced.