'northeastern' originates from Old English, specifically the words 'norþ' meaning 'north' and 'east' meaning 'east', combined with the suffix '-ern' to denote direction.

'norþ' and 'east' combined in Old English to form 'northeastern', which has remained largely unchanged in modern English.

Initially, it meant 'toward the northeast direction', and this meaning has largely remained the same in modern usage.