noun

a situation, typically one involving opposing parties, in which no progress can be made.

an attempt to break the deadlock

stalemate,impasse,checkmate,stand-off,standstill,halt,stop,stoppage,cessation,dead end,full stop

verb

cause (a situation or opposing parties) to come to a point where no progress can be made because of fundamental disagreement.

the meeting is deadlocked

tie,draw,dead heat