1)The act of a person inserting one or more fingers into either a womans vagina, or a man (or woman's) anus. When done on a woman, results in "orgasmic pleasure" derived from the motion of the finger rubbing against the clitoris.
The fingers are put together, and when inserted from above, enter the vagina in a hook shape, and then go in and out to give a maximum amount of pleasure to the woman. The consequences of a good fingering are fingers smelling like catfish, and a good blowjob from the recipient in gratitude.
Also see "eat out".
2) Each of the four slender jointed parts to either hand (or five if thumb is included)
1) "She wouldn't give me a blowjob unless I fingered her first"
2) Fingering a girl without fingers is just wierd