insubstantial
1. [ adjective ] lacking material form or substance; unreal
Synonyms: unreal unsubstantial
Examples:

"as insubstantial as a dream" "an insubstantial mirage on the horizon"

Related terms: substantial shadowy aeriform paper immaterial substantiality
2. [ adjective ] lacking in nutritive value
Synonyms: jejune
Examples:

"the jejune diets of the very poor"

Related terms: unwholesome
Similar spelling:   insubstantially
  insubstantiality