'longing' originates from Old English, specifically the verb 'langian', where 'lang' meant 'long' (in the sense of length or duration) and the suffix '-ian' formed verbs meaning 'to be long / to yearn'.

'longing' changed from Middle English forms such as 'longyng' (from Old English 'langian') and eventually became the modern English noun and participle 'longing'.

Initially, related to being 'long' in length or duration and to 'desire' generally; over time it specialized to mean an emotional yearning or strong desire, and as a noun came to denote the feeling itself.