'settleable' originates from Modern English, specifically formed from the verb 'settle' and the suffix '-able', where 'settle' came from Old English elements meaning 'to cause to sit/place' and '-able' (via Old French) comes from Latin '-abilis' meaning 'capable of'.

'settleable' was formed by attaching the productive adjectival suffix '-able' to the verb 'settle'. The verb 'settle' itself developed from Old English 'setlan'/'setlian' (related to 'setl' meaning 'seat'), passed through Middle English forms such as 'setlen'/'setlen', and became Modern English 'settle'; the suffix '-able' entered English via Old French from Latin.

Initially, 'settle' had senses related to 'making sit' or 'placing' (from Old English), but over time the verb broadened to include 'establish', 'resolve', and 'pay', and 'settleable' now carries the general meaning 'capable of being settled' (resolved, paid, or allowed to settle).