insubstantial (adj.) Look up insubstantial at Dictionary.com
c. 1600, from Medieval Latin insubstantialis "not substantial," from in- "not" (see in- (1)) + Late Latin substantialis "having substance or reality, material," in Late Latin "pertaining to the substance or essence," from substantia "being, essence, material" (see substance). Related: Insubstantially.