S: TheTimes – https://www.thetimes.co.uk/article/full-of-beans-costa-coffee-has-more-caffeine-than-red-bull-fvc3m79ld (last access: 8 April 2020); TheGuardian – https://www.theguardian.com/commentisfree/2019/oct/17/is-drinking-coffee-safe-during-your-pregnancy-get-ready-for-some-nuance (last access: 8 April 2020).
N: 1. 1830, from German Kaffein, coined by chemist F.F. Runge (1795-1867), apparently from German Kaffee “coffee”. So called because the alkaloid was found in coffee beans; its presence accounts for the stimulating effect of coffee and tea. The form of the English word may be via French caféine.
2. Caffeine, nitrogenous organic compoundof the alkaloid group, substances that have marked physiological effects. Caffeine occurs in tea, coffee, guarana, maté, kola nuts, and cacao.
3. Pure caffeine (trimethylxanthine) occurs as a white powder or as silky needles, which melt at 238 °C (460 °F); it sublimesat 178 °C (352 °F) at atmospheric pressure. It is very soluble in hot water; upon cooling, the solution deposits crystals of caffeine monohydrate. Caffeine is generally less soluble in organic solvents than in hot water. It is odourless but has a bitter taste.
4. Caffeine is readily obtained by the extraction of tea dust and as a by-product in the manufacture of decaffeinated coffee.
S: 1. OED – https://www.etymonline.com/search?q=caffeine (last access: 3 April 2020). 2&3. EncBrit – https://www.britannica.com/science/caffeine (last access: 11 April 2020). 4. Termium Plus – https://www.btb.termiumplus.gc.ca/tpv2alpha/alpha-eng.html?lang=eng&i=1&srchtxt=caffeine&codom2nd_wet=1#resultrecs (last access: 3 April 2020).
SYN: theine, methyltheobromine, guaranine, thein. (depending on context)
S: Termium Plus – https://www.btb.termiumplus.gc.ca/tpv2alpha/alpha-eng.html?lang=eng&i=1&srchtxt=caffeine&codom2nd_wet=1#resultrecs (last access: 11 April 2020).