The word "wast" is an outdated variant of "waste" and when used in the phrase "wast in flower", it means a flower that has wilted or is not flourishing anymore. The spelling of the word "wast" follows the IPA transcription of /weɪst/ and is pronounced as "wayst". The silent "e" at the end of the word denotes that the "a" should be pronounced as a long vowel sound. However, this spelling variant is not commonly used nowadays and has been replaced by the more modern "waste".