frail has 5 distinct synonyms spread across 2 of its 5 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. Its one recorded opposite is robust.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
the weight of a frail (basket) full of raisins or figs; between 50 and 75 pounds
a basket for holding dried fruit (especially raisins or figs)
Synonyms, antonyms and the broader and narrower relations for frail come from Princeton University’s WordNet. Full sources and licences.