Insubstantial (adjective)

1. Lacking substance or material of which something can be made.
2. Not having a solid or strong foundation.

Origin:

From latin insubstantialis, from in- ("not") + substantialis ("of substance, real, substantia.l")

Examples:

1. The argument was insubstantial, based on speculation and hearsay.
2. The building was insubstantial, made of flimsy materials and poorly constructed.
3. The evidence against him was insubstantial, and the case was dismissed.
4. The report was insubstantial, with little actual data to support the conclusions.
5. The meal was insubstantial, consisting of only a bowl of soup and a piece of bread.