The word "more decagonal" is spelled /mɔr dɛˈkæɡən(ə)l/. The first syllable "more" is pronounced as "mawr", with an open o sound. The second syllable "deca" is pronounced as "dek-uh" with the stress on the first syllable. The third syllable "gon" is pronounced as "gahn". The fourth syllable "al" is pronounced as "uhl". Overall, the word refers to a shape or object with ten sides or angles, and the correct phonetic transcription helps ensure proper pronunciation.
The word decagonal comes from combining the Latin word decem, meaning ten, with the Greek word gonia, meaning corner or angle. Decagon refers to a geometric shape with ten sides and ten angles.
However, the phrase more decagonal doesn't have a specific etymology since it is a combination of the comparative adjective more and the noun decagonal. It simply means more like a decagon or having more characteristics of a decagon.