'backyarder' originates from English, specifically the word 'backyard' plus the agentive suffix '-er', where 'back' meant 'the rear' and 'yard' meant 'an enclosed area or plot of ground'.

'backyarder' was formed by adding the productive English agentive suffix '-er' to the compound noun 'backyard' (itself from 'back' + 'yard'), creating a noun meaning 'one associated with the backyard' and evolving into the modern informal term 'backyarder'.

Initially, the elements simply denoted location ('back' + 'yard'); over time the derived noun came to denote a person characterized by activities in that space, especially informal gardening or small-scale keeping of animals — the modern sense of 'someone who uses a backyard for gardening or small-scale farming'.