The term "ex-chequer" denotes the treasury or financial department of a government. Some antonyms or opposite words for this term could include "deficit," "debt," or "insolvency." These words are often used to describe situations where finances are unstable, unbalanced, or negative. On the other hand, words like "surplus," "wealth," or "prosperity" could be considered antonyms or opposites to ex-chequer when used to describe a government's financial situation. In general, antonyms for ex-chequer tend to be words that connote financial instability, while opposites tend to describe prosperity and economic growth.