1. having no definite form or distinct shape (Freq. 3) - amorphous clouds of insects - an aggregate of formless particles - a shapeless mass of protoplasm • Syn: amorphous, formless • Similar to: unformed • Derivationally related forms: shapelessness 2. lacking symmetry or attractive form - a shapeless hat on his head • Similar to: unshapely • Derivationally related forms: shapelessness