A bong (also conduit, billy, bing, or moof) is really a filtration device generally employed for smoking cannabis, tobacco, and other herbal substances. From the bong shown inside the photo, the gas flows from your lower port on the left for the upper port around the right.
In construction and performance a bong is comparable to a hookah, except smaller and also more portable. A bong could possibly be made out of any air- and water-tight vessel with the addition of a bowl and stem apparatus (or slide) which guides air downward to below level whence it bubbles upward ("bubbler") during use. To get oxygen in to the bong and harvest the last remaining smoke, an opening referred to as "carburator", "carb", "choke", "bink", "rush" "shotty" "kick hole" or simply just "hole", somewhere for the lower section of the bong above level, is first kept covered throughout the smoking process, then opened to permit the smoke to be drawn to the respiratory system.
The saying bong is definitely an adaptation from the Thai word bong or baung, which identifies a cylindrical wooden tube, pipe, or container cut from bamboo, and this means the bong useful for smoking.
Bongs have been in use by the Hmong, in Laos and Thailand, and over Africa for years and years. One of the earliest recorded reasons like the saying in the West influences McFarland Thai-English Dictionary, published in the mid 1940s, which describes one of many meanings of bong inside the Thai language as, "a bamboo waterpipe for smoking kancha, tree, hashish, or hemp-plant." A January 1971 publication of the Marijuana Review also used the phrase.