utmost; extremely ~
Expresses that something is the utmost or extreme of a feeling, often in fixed formal phrases.
の至り is a very formal, written expression used to say that a feeling is at its highest degree. It appears in set phrases like 感激の至り (utmost gratitude) or 恐縮の至り (deeply honored). You use it when you want to sound highly respectful and humble, often in speeches, official letters, or ceremonial contexts. It is not used in everyday conversation; saying it to a friend would sound strange and overly stiff. Because it is limited in what nouns it can attach to, learning the common phrases is more practical than trying to create new combinations.