Your middle finger. The finger you give the finger with. Also possibly the finger you digit-fuck someone with.
He put out his hand and extended his fuckfinger right in my face.
A derogatory term used to describe someone who is less than satisfactory in their behaivour. Originated from the middle finger of a female, which is normally used to insert into their vagina or anus to pleasure themselves. Normally, has sticky residue and horrific odours as a result of not cleaning it.
You fuckfinger, why the hell did you root my nana!?