shapeless

From shape +‎ -less.

shapeless (comparative more shapeless, superlative most shapeless)

1. Without a clearly defined or identifiable shape.
   • 1976, Records in Review, page 407:

     If you skip the prelude, which is at once rhythmically square and shapeless, this Lohengrin starts out decently enough, for Hans Helm is one of the okayest Heralds on disc (a modest compliment, to be sure).

• amorphous, formless; see also Thesaurus:amorphous

• phaseless