The spelling of the word "wast on the air" can be broken down phonetically using IPA transcription. The word starts with the "w" sound, followed by the "ah" sound as in "father." Then, the "s" sound is represented by the letter "s," followed by the "t" sound. Finally, the word concludes with the "on" sound as in "gone" and the "air" sound as in "hair." When pronounced all together, the word is phonetically written as /wɑst ɑn ði ɛr/.