'dockable' originates from English, formed from the noun/verb 'dock' + the suffix '-able' (from Latin '-abilis' via Old French), where '-able' meant 'capable of'.

'dock' came into English from Middle Dutch 'dok' and Middle English 'dok', referring to a dock or dry dock; the productive adjectival suffix '-able' is from Latin '-abilis' through Old French and was attached to 'dock' in Modern English to form 'dockable'.

Initially it meant 'capable of being placed in or secured to a dock' (a maritime sense); over time the formation '-able' extended the sense to other contexts, giving the modern additional sense 'capable of being attached or fixed (e.g., user-interface elements)'.