'chaser' originates from English, specifically from the verb 'chase' with the agentive suffix '-er', where 'chase' itself comes from Old French 'chacier' (to hunt) and ultimately from Latin roots related to 'capere' (to take, seize).

'chase' passed from Old French 'chacier' into Middle English (forms like 'chasen'/'chacen') and became modern English 'chase'; the agentive suffix '-er' was then added to form 'chaser'.

Initially, the root meant 'to hunt or seize'; over time it broadened to mean 'to pursue' in general and developed derived senses such as an object or person used to follow (a 'chaser') and, by extension, a mild drink taken after a stronger one.