When things come to a grinding halt, it means they have abruptly stopped. There are a number of synonyms for this phrase that can be used in a similar context. For example, the word "standstill" can be used to describe a situation where things have come to a complete stop. "Stagnation" can also be used to describe situations where progress is being halted or stunted. Another possible synonym is "gridlock," which refers to traffic jams or other situations where movement is severely limited. Finally, "deadlock" can be used to describe situations where two parties are unable to come to an agreement or find a way forward.