plural of sac à dos

(informal, figuratively) to be a convenient excuse, to be a good excuse, to be a convenient scapegoat, to be easily blamed (to be just the right person to put the blame on, even when innocent)

(figuratively) to have one's back to the wall, to be up against the wall, to be backed into a corner, to have no way out

to hunker down; to ride the storm out; to hold still until the storm is over; to wait and see; to grin and bear it

behind someone's back

at the expense of

(intransitive, of a cat) to arch one's back / (intransitive, idiomatic) to weather the storm, lie low

(transitive) to antagonise someone, to get on someone's bad side

(idiomatic) to cost an arm and a leg: to cost too much, to be very expensive

(informal) (transitive with de) to be fed up to the back teeth (with) / (informal) extenuated by or after a hard manual work