Canadian raising

Noun

 * 1)  The phenomenon in some dialects of English, especially, in which  is realized as  and/or  is realized as  or  before underlying unvoiced consonants.
 * 2)  A similar but more restricted phenomenon, found in most dialects of, that applies only to , which is realized as  in certain contexts, especially before underlying unvoiced consonants but with significant speaker-to-speaker variation.