'ring-closure' originates from Modern English, specifically the words 'ring' and 'closure', where 'ring' meant 'a circular band' and 'closure' derives from 'close' meaning 'to shut or make closed.'

'ring' comes from Old English 'hring' meaning 'a ring, circle'; 'closure' derives from Latin 'claudere' via Old French 'clore' and Middle English 'clos/close', eventually becoming the modern English 'closure'. The compound 'ring-closure' developed in scientific usage in Modern English to describe the act or result of forming a ring.

Initially, the elements referred simply to a 'ring' and the act of 'closing' (i.e., shutting). Over time, in scientific contexts the compound came to mean specifically 'the formation of a cyclic molecular structure' (especially in organic chemistry).