clutter (v.)

1550s, "to collect in heaps, crowd together in disorder," variant of clotern "to form clots, to heap on" (c. 1400); related to clot (n.), and perhaps influenced by cluster. Sense of "to litter, to crowd (a place) by a disorderly mass of things" is first recorded 1660s. Related: Cluttered; cluttering.

1570s, "things lying in heaps or crowded confusion," from clutter (v.).