'lentiform' originates from Neo-Latin, specifically the word 'lentiformis', where 'lens' (Latin 'lent- / lentis') meant 'lentil' and '-formis' meant 'shape' or 'form'.

'lentiform' entered English from Neo-Latin 'lentiformis' (formed from Latin 'lens, lentis' meaning 'lentil' plus Latin suffix '-formis'), and was adapted into English as the adjective 'lentiform'.

Initially, it meant 'having the shape of a lentil'; over time this meaning has remained largely unchanged and is still used to mean 'lens-shaped' in modern English.