Crossword clue: the excess of weight of that part of a canon behind the trunnions over that in front of them.
2 answers found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).
Possible answers
exceeding in heaviness; having greater weight
The excess of weight of that part of a canon behind the trunnions over that in front of them.