Webster's Revised Unabridged Dictionary · 1913

deadlock

deadlock , noun

1.
A lock which is not self-latching, but requires a key to throw the bolt forward.
2.
A counteraction of things, which produces an entire stoppage; a complete obstruction of action.
Things are at a deadlock. — London Times
The Board is much more likely to be at a deadlock of two to two. — The Century