'bailout' originates in English as a compound of the verb 'bail out' (bail + out), where 'bail' originally had senses such as 'to remove water from a boat' and 'to free someone by providing bail; to deliver or hand over' (from Old French roots meaning 'to hand over').

'bail out' was used as a verb phrase in earlier English (examples include literal senses such as removing water from a boat and freeing someone by paying bail). The noun 'bailout' developed later as a compound noun in the 20th century and became common in the financial sense (especially mid-to-late 20th century onward), gaining wide use during major financial crises.

Initially it referred to literal acts of bailing (removing water) or freeing someone by paying bail; over time it broadened and shifted to mean 'an emergency rescue, especially financial assistance' and is now commonly used for government or institutional financial rescues.