'forwardable' originates from English, specifically formed from the word 'forward' plus the suffix '-able', where 'forward' ultimately comes from Old English 'forweard' meaning 'toward the front' and the suffix '-able' derives from Latin '-abilis' (via Old French) meaning 'capable of'.

'forwardable' developed by combining Middle/Modern English 'forward' (from Old English 'forweard') with the productive adjectival suffix '-able' (from Latin through Old French), resulting in the modern English formation 'forwardable'.

Initially, the root 'forward' meant 'toward the front' or 'in advance'; with the suffix '-able' the compound meaning evolved into 'capable of being forwarded' (i.e., able to be sent on).