incessant
in-SES-untadjMeaning never stopping, often to the point of annoyance
Memory hook IN-CESS-ANT: the ANTS never CEASE. The ants march across the picnic blanket all day long, never stopping for a moment. Their marching is incessant.
The puppy’s incessant barking went on all night without a single pause.
In context After three days of incessant rain, without even an hour of sunshine, the creek rose over the road.
Similar nonstop, constant, unending, ceaseless
Opposite occasional, intermittent, sporadic
From Latin incessans, “unceasing”: in- (not) + cessare (to stop).