silt

Short definition from Wiktionary

Noun

1. 1
   Mud or fine earth deposited from running or standing water.
2. 2
   Any material with similar physical characteristics, regardless of its origins or transport.
3. 3
   A particle from 3.9 to 62.5 microns in diameter, following the Wentworth scale.

Verb

1. 1
   To clog or fill with silt.
2. 2
   To become clogged with silt.
3. 3
   To flow through crevices; to percolate.