Not up to expectations:
— A disappointing performance from one who had seemed so promising.

synonyms: dissatisfactory, unsatisfying.

Roget 832: discontented; dissatisfied etc. v.; unsatisfied, ungratified; dissident; dissentient etc. 489; malcontent, malcontented, exigent, exacting, hypercritical.    repining etc. v.; regretful etc. 833; down in the mouth etc. (dejected) 837.    in high dudgeon, in a fume, in the sulks, in the dumps, in bad humor; glum, sulky; sour as a crab; soured, sore; out of humor, out of temper.    disappointing etc. v.; unsatisfactory.    frustrated (failure) 732.    ... show more