IPA: /ˈstrʌk.tʃər.ləs/
KK: /ˈstrʌk.tʃər.ləs/
Not having a clear or organized form or arrangement.
The artist created a structureless piece that allowed for free expression.
Structureless → It is formed from "structure" (from Latin "structura", meaning a building or arrangement) and "-less" (meaning without). The word "structureless" means lacking a defined arrangement or organization.
Think of something that is 'without' ('-less') a 'building' or 'arrangement' ('structure') — that's why structureless means lacking structure.