adverb, noun, used as a suffix
Formal or literary adverb/suffix meaning 'extremely'. Often used in set phrases like 至極当然 (perfectly natural) or 至極簡単 (extremely simple).
彼の提案は至極当然なものだった。
His proposal was perfectly natural.
その説明は至極簡単で、誰にでも理解できた。
noun which may take the genitive case particle 'no', na-adjective, noun
Noun/adjectival noun meaning the highest degree or the best. Often used in formal contexts like 至極の一品 (a supreme item) or 至極の栄誉 (the highest honor).
この茶碗は至極の出来栄えだ。
This tea bowl is of supreme craftsmanship.
彼は至極の栄誉に浴した。
He was granted the highest honor.
The explanation was extremely simple and anyone could understand it.
Compound of 至 (itari, 'arrival, extreme') and 極 (kiwami, 'extreme'). The exact historical derivation is uncertain, but the combination reinforces the meaning of 'utmost'.