bull has 20 distinct synonyms spread across 9 of its 15 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 bear.
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.
a serious and ludicrous blunder
“he made a bad bull of the assignment”
the second sign of the zodiac; the sun is in this sign from about April 20 to May 20
a formal proclamation issued by the pope (usually written in antiquated characters and sealed with a leaden bulla)
mature male of various mammals of which the female is called `cow'; e.g. whales or elephants or especially cattle
try to raise the price of stocks through speculative buying
Synonyms, antonyms and the broader and narrower relations for bull come from Princeton University’s WordNet. Full sources and licences.
speak insincerely or without regard for facts or truths
“The politician was not well prepared for the debate and faked it”