clunk 
/ˈklʌŋk/ noun
plural clunks /ˈklʌŋk/ noun [count] : a loud, dull sound that is made when a heavy object hits another object or a surface
▪ The book hit the floor with a loud clunk.
▪ The book hit the floor with a loud clunk.
— clunk verb, clunks; clunked; clunk·ing
[no obj] ▪ The car door clunked shut. [+ obj] ▪ The ball clunked [=hit] him on the head.
[no obj] ▪ The car door clunked shut. [+ obj] ▪ The ball clunked [=hit] him on the head.
