CLUNK
thump, thumping, clump, clunk, thud
(noun) a heavy dull sound (as made by impact of heavy objects)
clop, clump, clunk, plunk
(verb) make or move along with a sound as of a horseās hooves striking the ground
Source: WordNet® 3.1
Noun
clunk (plural clunks)
A dull, metallic sound, especially one made by two bodies coming into contact.
(dated) The sound of liquid coming out of a bottle, etc.; a glucking sound.
Verb
clunk (third-person singular simple present clunks, present participle clunking, simple past and past participle clunked)
to make such a sound
Source: Wiktionary