bill has 33 distinct synonyms spread across 10 of its 13 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. WordNet records no antonym for it — antonymy is a relation between word forms rather than concepts, so it is deliberately sparse.
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 statute in draft before it becomes law
“they held a public hearing on the bill”
an itemized statement of money owed for goods shipped or services rendered
“he paid his bill and left”
a piece of paper money (especially one issued by a central bank)
“he peeled off five one-thousand-zloty notes”
the entertainment offered at a public presentation
a list of particulars (as a playbill or bill of fare)
advertise especially by posters or placards
“He was billed as the greatest tenor since Caruso”
Synonyms, antonyms and the broader and narrower relations for bill come from Princeton University’s WordNet. Full sources and licences.