Witherso is not a commonly used word in modern English. It can be spelled as "wither so" and used to mean "in whichever way" or "by whatever means." The IPA phonetic transcription reveals that the pronunciation of witherso is /wɪðərsəʊ/. The first syllable is pronounced as "wih" with a short "i" sound, followed by "th" pronounced as "ð." The second syllable is pronounced as "er," and lastly, "so" is pronounced as "sow" with a long "o" sound.