A word used by the Sherlock fandom for the overwhelming feels that come along with watching the BBC Sherlock season 2 final episode The Reichenbach Fall, in which Sherlock commits suicide.

It is revealed later that Sherlock did not actually commit suicide but faked it, but you will still have Reichenfeels even if you know that Sherlock isn't actually dead. May include:

Sadness
Severe depression
Uncontrollable crying
Grief
Heartache

When some little bitchboy is acting like a little tiny pee pee poo poo baby and messing up the group plans.