Yesterseason is a term used to refer to the previous season or year. The spelling of this word can be explained using the International Phonetic Alphabet (IPA). The first syllable "yester" is pronounced as /ˈjɛstər/, with the "y" sound represented by the "j" symbol in IPA. The second syllable "season" is pronounced as /ˈsiːzən/, with the long "e" sound represented by the "i" symbol in IPA. Overall, the spelling of yesterseason is phonetically accurate and easy to understand.