'gas-relief' is a compound formed from 'gas' + 'relief'. 'gas' in modern English dates from the 17th century (see below) and 'relief' comes from Old French and Latin roots meaning 'to raise up' or 'alleviate'.

'gas' was coined in the early 17th century (attributed to Jan Baptist van Helmont) and entered English via Neo-Latin/Dutch; 'relief' came into English from Old French 'releve'/'relief' and from Latin 'relevare' ('re-' + 'levare' meaning 'to raise'). The compound 'gas relief' is a straightforward modern English combination that became common with over-the-counter remedies in the 19th–20th centuries.

Individually, 'gas' originally named the physical phenomenon (term coined in the 1600s) and 'relief' meant 'raising' or 'alleviation'; together the compound came to mean either the easing of gas-related discomfort or products intended to produce that easing.