initial consonant combination used in Old English (the Clark Hall dictionary has 82 entries under cn-), but not now admitted in speech, the n- only being sounded. In Middle English spelling all were lost or turned to kn-. It also is retained in the spelling of some Latinized words from Greek, where initial kn- was common.
respelling of Old English hw- attested from 11c., but not the common form until after c. 1400. It represents PIE *kw-; in German reduced to simple w-, in Scandinavian as hv-, kv-, or v-.
It also was added unetymologically to some borrowed words (whisk, whiskey) and some native words formerly spelled with simple w- or h- (whole, whore). In the 15c. flowering of its use it also threatened to change the spelling of hot, home and many more. In northern English 16c.-18c., sometimes altered to quh- (see Q). Proper pronunciation has been much in dispute in educated speech.
word-forming element of verbs and nouns from verbs, with a wide range of meaning: "about, around; thoroughly, completely; to make, cause, seem; to provide with; at, on, to, for;" from Old English be- "about, around, on all sides" (the unstressed form of bi "by;" see by (prep.)). The form has remained by- in stressed positions and in some more modern formations (bylaw, bygones, bystander).
The Old English prefix also was used to make transitive verbs and as a privative prefix (as in behead). The sense "on all sides, all about" naturally grew to include intensive uses (as in bespatter "spatter about," therefore "spatter very much," besprinkle, etc.). Be- also can be causative, or have just about any sense required. The prefix was productive 16c.-17c. in forming useful words, many of which have not survived, such as bethwack "to thrash soundly" (1550s) and betongue "to assail in speech, to scold" (1630s).