The act of plugging your nose and pushing out of it, popping your ears and going getting blurry vision, as well as decreased hearing ability. This will cause you to acquire a short and sweet, "buzz", before regaining your senses and returning to reality.
A 50mm prime camera lens with an f-number of 1.8 or lower. The first lens to earn this nickname was the Canon EF 50mm f/1.8 II, introduced in 1991. Nifty fifties are cheap to buy, have sharp optics, and give amazing bokeh.