1 of a boat : floating on the water without being tied to anything or controlled by anyone
We could see a ship adrift [=drifting] in the storm.
The canoe was set/cast adrift from its moorings.
2 : without guidance, purpose, or support
She was alone and adrift in the city.
Many workers were cast adrift by massive layoffs.
3 British : behind by a specified amount in a race, competition, etc.
He was eight points adrift (of the leader).
come adrift chiefly British
: to become loose or unattached
One of the straps on her dress came adrift.