(figuratively, informal, of people) not to line up, not to queue up, not to crowd in, not to fall over each other (with the implied meaning that something meets with little success)

(informal) to tie oneself in knots, to worry oneself sick

the proof of the pudding is in the eating

Alternative form of il n'y a pas le feu au lac

to change horses in midstream

ISIS/ISIL (Islamic State)

(idiomatic) to lose one's temper

(figuratively) to feel nauseous, to feel like one is going to vomit

to play cat and mouse

a leopard cannot change its spots