frozen has 10 distinct synonyms spread across 4 of its 7 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 unfrozen.
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.
turned into ice; affected by freezing or by long and severe cold
“the frozen North”
(used of foods) preserved by freezing sufficiently rapidly to retain flavor and nutritional value
“frozen foods”
incapable of being changed or moved or undone; e.g. "frozen prices"
“living on fixed incomes”
2 of the 7 recorded senses carry no synonym, antonym or related term, so they are not shown above. Every sense, with its definition and examples, is on the full entry for frozen.
Synonyms, antonyms and the broader and narrower relations for frozen come from Princeton University’s WordNet. Full sources and licences.