word-forming element meaning "social, of society; social and," also "having to do with sociology," from combining form of Latin socius "companion, ally, associate, fellow, sharer," from PIE *sokw-yo-, suffixed form of root *sekw- (1) "to follow." Common in compounds since c. 1880.
medical word-forming element meaning "slow, delayed, tardy," from Greek bradys "slow;" as in bradycardia (1890), with Latinized form of Greek kardia "heart;" bradykinesia, "slow movement," with Greek kinēsis "movement, motion;" bradypnea, with Greek pneo/pnein "to breathe."
word-forming element meaning "race, culture," from Greek ethnos "people, nation, class, caste, tribe; a number of people accustomed to live together" (see ethnic). Used to form modern compounds in the social sciences.
consonant sound in some English words derived from Greek. The p- typically is silent in English but pronounced in French, German, Spanish, etc.
It is to be desired that it were sounded in English, also, at least in scientific and learned words; since the reduction of pneo- to neo-, pneu- to new-, and pnyx to nix, is a loss to etymology and intelligibility, and a weakening of the resources of the language. [OED]
before vowels xyl-, word forming element meaning "wood," from Greek xylon "wood cut and ready for use, firewood, timber; piece of wood; stocks, a plank, beam, or bench," in New Testament, "the Cross," a word of uncertain origin. It seems to correspond with Lithuanian šulas "post, pole, stave," Russian šulo "garden-pole," Serbo-Croatian šulj "block," Old High German sul "style, pole," Gothic sauls "pillar," but the exact relationship is unclear, and Beekes asks, "Was the word taken from a non-IE substrate language?"