'tarless' originates from the English word 'tar' combined with the suffix '-less', where 'tar' refers to a dark, thick, flammable liquid distilled from wood or coal, and '-less' means 'without'.

'tar' combined with the suffix '-less' in Middle English to form 'tarless', maintaining its meaning of 'without tar'.

Initially, it meant 'without tar', and this meaning has largely remained the same in modern usage.