yiffing

Verb

yiff (third-person singular simple present yiffs, present participle yiffing, simple past and past participle yiffed)

1. (informal, intransitive, slang) To bark as or similar to a fox.
2. (ambitransitive, informal, rare, vulgar) Of animals, especially foxes, to mate
   • Monsters snicker at me, succubi refuse to be seen with me, my dog tries to yiff my leg, shopkeepers say ‘No shirt, no shoes, no service’.1997 October 17, StarChaser, “What to genocide”, in rec.games.roguelike.nethack (Usenet), message-ID <3448af39.75668367@169.132.11.13>
3. (ambitransitive, informal, slang, vulgar) Of furries, To have sexual intercourse.
   • I mean, the urge to yiff is a pretty weird thing to admit to. Not something you can just drop into conversation. But look at them, hundreds of them, all gathered together in a Vegas hotel, exchanging information and experiences, the knowledge of their rare urges ever growing.2012, Joanne Reay, Romeo Spikes
4. (informal, intransitive, slang, transitive) To propose cybersex to someone.

See all 9 meanings of yiff