unreal vs insubstantial

unreal and insubstantial both are adjectives.

Word	Noun	Adjective	Verb	Adverb
unreal	No	Yes	No	No
insubstantial	No	Yes	No	No

As adjectives, unreal and insubstantial are synonyms defined as:

Other synonyms of unreal include unsubstantial.

unreal (adjective)	insubstantial (adjective)
lacking in reality or substance or genuineness; not corresponding to acknowledged facts or criteria	lacking material form or substance; unreal
not actually such; being or seeming fanciful or imaginary	lacking in nutritive value
lacking material form or substance; unreal	lacking solidity or strength
contrived by art rather than nature