Thud

Webster's Dictionary of the English Language

·add. ·vi & ·vt To make, or strike so as to make, a dull sound, or thud.

II. Thud ·noun A dull sound without resonance, like that produced by striking with, or striking against, some comparatively soft substance; also, the stroke or blow producing such sound; as, the thrud of a cannon ball striking the earth.