'pro-gun-control' originates from a combination of elements: 'pro-' originates from Latin 'pro' meaning 'for' (supporting), 'gun' comes via Middle English 'gonne' (an early word for a firearm), and 'control' comes from Old French 'controle' (from Medieval Latin 'contrarotulare') meaning 'to check against a roll'.

'pro-' (Latin 'pro') was attached as a combining form in modern English to indicate support; 'gun' developed from Middle English 'gonne' referring to early firearms; 'control' passed from Old French 'controle' into Middle English and came to mean 'to regulate' or 'to exercise authority over', producing the modern compound phrase 'pro-gun-control'.

Initially, 'pro-' simply denoted 'for' and 'control' meant 'checking or regulating'; combined in modern political usage the phrase came to mean 'in favor of regulations that restrict access to firearms' and has a distinctly political connotation.