'itch-relieving' is a modern English compound formed from 'itch' + 'relieve'. 'relieve' comes from Old French (e.g. 'relever') ultimately from Latin 'relevare' (re- + levare 'to raise, lighten'), where the sense of 'lighten' extended to 'alleviate'.

'itch' derives from Old English (related forms meaning 'to itch' used for the sensation of pruritus), while 'relieve' entered Middle English via Old French; the noun/verb roots combined in Modern English to form compounds such as 'itch-relieving' (20th century onward) to describe topical or medicinal effects.

Individually, 'itch' denoted the sensation and 'relieve' originally meant 'to raise or lighten', which shifted toward 'alleviate'; combined, 'itch-relieving' now specifically means 'reducing or soothing itch'.