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.

To make, or strike so as to make, a dull sound, or thud.

The F-105 Thunderchief was always called the Thud by those who flew it. It was a single-engined jet fighter-bomber that carried the major load of strikes against North Vietnam.

THUD is an unlockable skater from Tony Hawk's Underground. It can be unlocked by finishing the game on Sick difficulty, or using the cheat code NOOO!!. It is a reptilian monster that, when selected on the skater selection screen, jumps out of a sewer, as seen in the before-game clip.

make a noise typical of an engine lacking lubricants

When a girl's giving you head, right after your blow your load down her throat, you pull out your still hard cock and smack her right between the eyes with it. It makes a nice thudding noise, hence the name. Strictly a class move, and to show her who's boss. - Bigdog, Illinois

THUD is a register transfer level simulation environment optimized for cycle- based designs. The design is expressed in TH, a Scheme-based hardware description language that supports 1/0/x operators and hierarchical instantiation. THUD can be used as a library, in batch mode, or through one of its interactive interfaces.

THuD - an Extensible TiVo Home Media Option Daemon