not substantial; specif.,
- not real; imaginary
- not solid or firm; weak or flimsy
Origin of insubstantialMedieval Latin insubstantialis
- Not firm or solid; weak or flimsy: a shed made of insubstantial materials.
- Very small or negligible, as in importance, size, or amount: an insubstantial volume of traffic.
- Lacking or appearing to lack substance or reality: “the insubstantial vapor of an autumn field” (Loren Eiseley).
(comparative more insubstantial, superlative most insubstantial)
in- + substantial