Insult, to inform someone of the fact they lost.

Popularized by the indie game Dwarf Fortress, "losing is fun" refers to the inevitable destruction of your fortress, wether by goblins, elves, kobolds, humans, demons, and more! It really is what keeps many players going, wondering what will destroy their new masterpiece.

to lower your(one's) credibility and image in front of others

To make a social blunder so bad, you drive away your friends, lose a great opportunity, become infamous, or an otherwise unpleasant consequence of a seemingly in consequent action

To stop acting rationally.

Like the insult grow a pair, only said to a girl acting particularly manly or that looks like a man. Also used to just make one mad.

When you think you have to fart and you end up shitting your pants