The spelling of the phrase "gat bigger" can be explained with IPA phonetic transcription. "Gat" is pronounced as /ɡæt/, with a hard "g" sound and a short "a" vowel sound. "Bigger" is pronounced as /ˈbɪɡər/, with a "b" sound, a short "i" vowel sound, a hard "g" sound, and a schwa sound at the end. This phrase means "become larger" and can be used to describe a variety of things, from physical objects to emotions.