Answer: stagnates

AnswerCrossword Clue
STAGNATESBecomes inactive
STAGNATESLacks activity
STAGNATESBecomes hidebound
STAGNATESStops flowing
STAGNATESStops developing
STAGNATESBecomes sluggish
STAGNATESLanguishes
stagnatesCease developing; become inactive or dull
stagnatesSTAGNATE, to become still and dull
stagnates(of water or air) Cease to flow or move; become stagnant