【 ごくごく・goku goku 】gulping sound
麦茶をごくごくと飲んだ。
(mugicha wo goku goku to nonda)
gulped down barley tea
ビールをごくごくと飲んだ。
(bīru wo goku goku to nonda)
I gulped down the beer.
*飲む (nomu) = drink
Japanese is rich in onomatopoeic expressions (4500!) and are useful for articulating a sound, state or emotion.