What is another word for auxiliary boiler?

It depends which auxiliary boiler you mean. In the sense “(nautical) an extra boiler (as a ship's boiler that is used while the ship is in port)”, the synonyms are donkey boiler. Across all 1 sense there are 1 distinct synonyms, and they are not interchangeable with each other — this page lists them under the sense each one belongs to.

What is the opposite of auxiliary boiler?

WordNet records no antonym for auxiliary boiler. Antonymy in WordNet is a relation between specific word forms rather than between concepts, so it is recorded only where lexicographers judged the pairing direct. An absence here means none was recorded, not that none can be imagined.

Where do the synonyms for auxiliary boiler come from?

From Princeton University's WordNet, a lexical database maintained by lexicographers since 1985. A synonym here means a word form that shares a synset with this word — a set of forms interchangeable in one recorded context. Nothing on this page is generated by a language model.

Synonyms and antonyms

auxiliary boiler

nounRare

auxiliary boiler has 1 distinct synonym spread across 1 of its 1 sense. 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.

1
Distinct synonym: 0
Antonyms: 1 of 1
Senses with a relation

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.