What is a synonym for flimsy?

Here are some synonyms for "flimsy," depending on the specific context:

General Weakness:

* Fragile

* Brittle

* Weak

* Delicate

* Thin

* Light

* Insubstantial

Lacking Substance:

* Superficial

* Hollow

* Unconvincing

* Weak

* Unfounded

* Frivolous

For Arguments or Evidence:

* Unfounded

* Baseless

* Shaky

* Weak

* Unsubstantiated

For Materials:

* Cheap

* Inferior

* Poor quality

* Lightweight

The best synonym depends on the specific meaning you want to convey.