n. 25B6; adjective
the constant background noise : CONTINUAL, continuous, persistent, sustained, round-the-clock; ceaseless, unceasing, perpetual, incessant, never-ending, eternal, endless, unabating, non-stop, unrelieved; interminable, unremitting, relentless.
a constant speed : CONSISTENT, regular, steady, uniform, even, invariable, unvarying, unchanging, undeviating, unfluctuating.
a constant friend : FAITHFUL, loyal, devoted, true, fast, firm, unswerving; steadfast, staunch, dependable, trustworthy, trusty, reliable, dedicated, committed.
constant vigilance : STEADFAST, steady, resolute, determined, tenacious, dogged, unwavering, unflagging.
fitful, variable, fickle.
25B6; noun dread of cancer has been a constant : UNCHANGING FACTOR, given.