lacking definite structure or organization
"an unstructured situation with no one in authority"
"a neighborhood gang with a relatively unstructured system"
"children in an unstructured environment often feel insecure"
"unstructured inkblots"
lacking the system or structure characteristic of living bodies
"The unstructured mass of cells in that tumor lacks any organized tissue architecture typical of healthy organs."
Lacking structure.
"The unstructured nature of the brainstorming session allowed everyone to share ideas freely without following a strict agenda."