'appendage-related' originates from Modern English, specifically the combination of the noun 'appendage' and the adjective-forming/relational element 'related'.

'appendage' ultimately comes from Latin 'appendere' (to hang upon), from ad- 'toward' + pendere 'to hang'. It passed into Old French and then Middle English as 'apendage'/'appendage' before becoming the modern English noun. The compound 'appendage-related' is a Modern English formation combining that noun with 'related'.

Initially, 'appendage' meant 'something hung on or attached' (from the literal sense of hanging). Over time it came to mean 'a subsidiary part or limb' in anatomy and general usage; 'appendage-related' therefore denotes things concerning such attached parts.