Synonyms of unstable in English:


See definition of unstable


1‘icebergs are notoriously unstable and may flip over’


unsteady, rocky, wobbly, wobbling, rickety, shaky, tottery, tottering, teetering, doddery, unsafe, unbalanced, unreliable, insecure, not secure, unfastened, unsecured, movable, precarious

Irish bockety


stable, steady

2‘the country suffered from unstable coffee prices’


changeable, volatile, variable, unsettled, fluctuating, inconstant, inconsistent, irregular, fitful, unpredictable, unreliable, fickle, capricious, mercurial, erratic, uncertain, wavering


stable, firm

3‘he was mentally unstable’


unbalanced, of unsound mind, mentally ill, deranged, demented, crazed, distracted, troubled, disturbed, unhinged, insane, mad, mad as a hatter, mad as a March hare, raving mad, lunatic, out of one's head, out of one's mind, not in one's right mind, neurotic, psychotic

non compos mentis

British sectionable

informal crazy, loopy, loony, mixed up, nuts, nutty, nutty as a fruitcake, bananas, cracked, crackpot, daft, dippy, screwy, bats, batty, dotty, cuckoo, bonkers, potty, mental, screwed up, not all there, off one's head, out to lunch, a bit lacking, round the bend, round the twist, away with the fairies

British informal barmy, crackers, barking, barking mad, off one's rocker, off one's trolley, daft as a brush, not the full shilling

North American informal nutsy, nutso, squirrelly, wacko, buggy

dated touched


stable, balanced