lub-dub

• lub-dup

The low-pitched, longer first heart sound forms lub. The higher-pitched, shorter second heart sound forms dub.

lub-dub

1. (onomatopoeia, medicine) Used to represent the normal rhythm of the heart on auscultation, comprising the first and second heart sounds.
   • 1982, Beverly Cleary, Ralph S. Mouse, New York, NY: HarperCollins, published 2000, →ISBN, page 51:

     Ralph tried to listen above the steady lub-dub, lub-dub of Ryan's heart, but soon he grew bored. Ryan's shirt was new and the flannel still fuzzy. Ralph nipped a hole in the front of the pocket for a better view and then, lulled by the muffled lub-dub, lub-dub and the steady rise and fall of Ryan's chest, fell asleep as if he were being rocked in a cradle.

• da-lub-dub, lub-da-dub, lub-dub-dam
• thump-thump

lub-dub (third-person singular simple present lub-dubs, present participle lub-dubbing, simple past and past participle lub-dubbed)

1. (intransitive) Of a heart, to beat.
   • 1992, Michael P. Ghiglieri, Canyon, Tucson, AZ: University of Arizona Press, →ISBN, page 237:

     I pulled my eyes away to glance downstream at a cinder cone perched at the brink of the left Esplanade above the mouth of Prospect Canyon and the still-hidden Lava Falls. My heart lub-dubbed a few beats quicker.