A pomelo is a crisp citrus fruit native to South and Southeast Asia. It is usually pale green to yellow when ripe, with sweet white (or, more rarely, pink or red) flesh and very thick rind and pith. It is the largest citrus fruit, 15–25 centimetres (5.9–9.8 in) in diameter, and usually weighing 1–2 kilograms (2.2–4.4 lb).
Coined in 1912 by the Polish biochemist Kazimierz Funk because it was suggested in 1912 that the organic micronutrient food factors that prevent beriberi and perhaps other similar dietary-deficiency diseases might be chemical amines. This proved incorrect for the micronutrient class, and the word was shortened to vitamin.