'rumour-related' originates from modern English, specifically formed by combining the noun 'rumour' and the adjective 'related' to mean 'related to a rumour'.

'related' derives from Latin 'relatus' (past participle of 'referre', 'to bring back') via Old French and Middle English; 'rumour' comes from Old French 'rumor' (or 'rumour') from Latin 'rumorem'/'rumor' meaning 'noise, report'. The compound 'rumour-related' is a recent English formation joining these elements.

Initially the elements referred separately to 'a report/noise' (rumour) and 'being connected' (related); the compound has come to mean specifically 'connected to unverified reports or gossip'.