not fresh; vapid or flat, as beverages; dry or hardened, as bread.

musty; stagnant

stale air.

having lost novelty or interest; hackneyed; trite

a stale joke.

having lost freshness, vigor, quick intelligence, initiative, or the like, as from overstrain, boredom, or surfeit

He had grown stale on the job and needed a long vacation.

Law . having lost force or effectiveness through absence of action, as a claim.

to make or become stale.

adjective

fresh , new , current , underused

adjective

dried , dry , faded , fetid , flat , fusty , hard , insipid , malodorous , musty , noisome , parched , rank , reeking , smelly , sour , spoiled , stagnant , stenchy , stinking , tasteless , watery , weak , zestless , antiquated , banal , bent , clich , clichd , clich-ridden , common , commonplace , corny * , dead , drab , dull , dusty , effete , hackneyed , like a dinosaur , mawkish , moth-eaten * , out * , pass , past , platitudinous , repetitious , shopworn , stereotyped , threadbare , timeworn , tired , trite , unoriginal , well-worn , worn-out , yesterday’s , bromidic , corny , overused , overworked , platitudinal , stereotypic , stereotypical , warmed-over , cliche , decayed , frowsy , humdrum , jejune , moldy , monotonous , passe , predictable , reworked , vapid , worn , wornout