A soldier or gunner trained to operate a culverin cannon.
From culverin plus the suffix -eer (from French -ier, meaning 'one who operates'), similar to 'musketeer.' This word appears in historical military texts from the 16th-17th centuries.
A culverineer was basically a specialized soldier—a gunner who trained specifically with these long, temperamental cannons, and the -eer suffix usually indicates someone with special skills or who operates a particular machine or weapon.
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