insubstantial vs unreal

insubstantial and unreal both are adjectives.

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

As adjectives, insubstantial and unreal are synonyms defined as:

Other synonyms of insubstantial include unsubstantial.

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