n. Like hyp. an abbreviation of hypochondria: commonly in the plural.n. In photography, a common abbreviation of hyposulphite of soda, a chemical extensively used in most photographic processes.n. A prefix of Greek origin, cognate with sub- of Latin origin, and meaning primarily ‘under,’ either in place or in degree (less,' ‘less than’).n. In the manufacture of india-rubber goods, a trade-name for lead thiosulphate, used as a vulcanizing material. Also known as black hypo.