From Longman Dictionary of Contemporary Englishthwackthwack /θwæk/ noun [countable] CSSOUNDa short loud sound like something hitting a hard surface —thwack verb [transitive]
Examples from the Corpus
thwack• The customary thwack on the bottom is still the best method for determining doneness.• He hit the flaring log such a hefty thwack that it broke in two.• From the next room came the thwack of darts and a louder hubbub of voices.• Rely more on the thwack than the look.• Somebody had procured an aluminum bat, and the traditional thwack surrendered to a whistling hum.Origin thwack (1500-1600) From the sound 