Main Entry:

un·sta·ble

Pronunciation:

\-ˈstā-bəl\

Function:

adjective

Date:

13th century

: not stable : not firm or fixed : not constant: as a: not steady in action or movement : irregular <an unstable pulse> b: wavering in purpose or intent : vacillating c: lacking steadiness : apt to move, sway, or fall <an unstable tower> d (1): liable to change or alteration <an unstable economy> <unstable weather> (2): readily changing (as by decomposing) in chemical or physical composition or in biological activity e: characterized by lack of emotional control

synonyms see inconstant

— un·sta·ble·ness noun

— un·sta·bly \-b(ə-)lē\ adverb