'lensless' originates from English, formed by combining 'lens' and the suffix '-less'. 'lens' itself comes from Latin 'lens' meaning 'lentil' (named for the shape of early lenses), and the suffix '-less' derives from Old English 'lēas' meaning 'without' or 'free from'.

'lensless' is a modern English compound created by joining the noun 'lens' (borrowed into English from Latin via Medieval/early Modern usage for the optical element) with the long-established Old English-derived suffix '-less'; there is no distinct medieval form of the full compound.

Initially it simply meant 'without a lens'; over time the literal meaning has remained, while usage has extended into technical contexts (e.g., 'lensless imaging') to denote methods or devices that function without conventional lenses.