ненадёжный

1) General subject: casual, dickey (о торговом предприятии и т. п.), dicky, fair weather, faithless, faltering, faltering speech, fast and loose, fickle, fly by night, fly-by-night, frail, incalculable, insecure, moonish, precarious, questionable, shakey, shaky, shifty, slippery (о человеке), slippy, straw, tickle, touch-and-go, treacherous, tricksy, tricky, trustless, truthless (о человеке), uncertain, undependable, uneasy, unreliable, unsafe, unsound, unsteady, unsure, untrustworthy, wacky, whacky, whiffler, wonky (о вещи), flimsy (a flimsy reference point), iffy, dark-minded, error-prone

2) Biology: fickle (напр. о культуре)

3) Colloquial: chancey, chancy, dicey

4) Dialect: huffy

5) Australian slang: suss

6) Psychology: versatile

7) Scottish language: uncanny

8) Jargon: fluffy, hairy, loose as a goose, wonky, flaky (о человеке), loose

9) Information technology: troublesome

10) Oil: unserviceable

11) Banking: junk (о ценных бумагах)

12) Household appliances: accident-sensitive

13) Automation: errorprone (напр. об элементе УЧПУ)

14) Quality control: fallible

15) Makarov: nondurable, pregnable, shady, unassured

16) Phraseological unit: bad apple