'near-synonym' originates from English, specifically combining 'near' and 'synonym', where 'near' meant 'close' and 'synonym' comes from Greek 'synonymon' meaning 'same-name'.

'synonym' came from Greek 'synonymon' (syn- 'together' + onoma 'name'), passed into Latin and French, and entered English as 'synonym' in the late 16th century; 'near' derives from Old English 'neah' (later 'near'); the compound 'near synonym' (later often hyphenated) developed in modern English.

Initially the elements referred to 'closeness' and 'same name/meaning', and over time the compound came to mean 'almost the same in meaning'—emphasizing closeness rather than exact identity.