Этимология () Yiff is part of a range of onomatopoeic words that form a pseudo-language used by the furry role-playing community: yiff, yip, yerf, yaff, yarf, growf, and growlf (in order from most positive connotations to most negative connotations). Yiff meant yes or an exuberant hello!. Later, yiff was assigned a meaning of a sexual proposition, a meaning that had previously been assigned to yipp (a coarse form of yip). Other claimed etymologies include:
* onomatopoeic word for the sound of a fox mating. This etymology is unsubstantiated and appears to be apocryphal.
* sense 3 of YIFF. This is apparently a backronym.