Wikipedia
Yunker Kotei Eki, , is a health tonic similar to Lipovitan and produced by the Sato Pharmaceutical Corporation in Japan. It was first produced in 1967, and is widely available at drug stores throughout Japan. Yunker contains Chinese herbal ingredients and caffeine and is marketed to the Japanese workforce to combat fatigue.
It is one of 33 tonics manufactured by Sato for a range of ailments related to fatigue. The Yunker line of tonics is also sold in the U.S., Europe and Singapore, but the contents of some tonics have been altered to meet domestic regulations.
A USDA report from 2002 reported that exports of Yunkeru Kotei-eki to six countries including the United States, Germany, Canada and Singapore were continuing to grow, and that Sato planned to start exports to Thailand later that year.
Usage examples of "yunker".
It was as if by behaving as a wildling yunker he could cheat death itself.