Electoral stasis is a condition that can arise when an electorate cannot realistically change its political composition, regardless of the swing occurring in a general election. A safe seat in a single member electoral system is one that is in electoral stasis.
In the context of electoral systems, stagnation can refer to a situation where the voting patterns of an electorate remain unchanged, even if there are shifts in the overall election results. A safe seat is often seen as a manifestation of this stability.