verb/ɛtʁ ɑ̃ byt/
to be exposed to, be subject to, be the butt of
“Aux plus âpres tourments un chrétien est en butte.” — A Christian is the object of the most bitter torments
XVIth century. a butte was a mound upon which archery targets were placed for shooting practice, hence figuratively, to be there is to be exposed to danger.