A confused disordered jumble of things.
Background echoes, from clouds etc., on a radar or sonar screen.
To utter words hurriedly, especially (but not exclusively) as a speech disorder (compare cluttering).
To fill something with clutter.
To make a confused noise; to bustle.
The state of being complex; intricacy; entanglement.
That which is and renders complex; intricacy; complication.