'poeticise' originates from English, formed from the adjective 'poetic' together with the verb-forming suffix from French 'iser' (later English '-ise'), where 'poetic' ultimately comes from Greek 'poietikos' meaning 'of or pertaining to poets' and the suffix meant 'to make' or 'to cause to be.'

'poeticise' developed from the adjective 'poetic' (from Old French/Latin/Greek roots) combined with the Romance/English verb-forming suffix '-ise'/'-ize' in early modern English; the related form 'poeticize' (US spelling) and earlier coinages meaning 'to make poetic' appeared in the 17th–19th centuries and stabilized as modern 'poeticise/poeticize.'

Initially it meant 'to render or style in the manner of poetry' and over time the sense broadened to include 'to romanticize or idealize' as a figurative extension.