say it: in-suhb-STAN-shuhl
insubstantial is an adjective meaning "lacking material form or substance; unreal". It carries 3 recorded senses.
lacking material form or substance; unreal
“as insubstantial as a dream”
“an insubstantial mirage on the horizon”
Definitions, synonyms and semantic relations for insubstantial come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.