The word for "兀" in English can be quite complex due to the nature of this character, which is primarily used in Chinese to denote a sense of isolation or independence. In a broader linguistic context, there isn't a direct equivalent in English, as the concept it represents is more abstract and less commonly expressed in the English language.

In mathematical terms, "兀" (pi) is the symbol used to represent the ratio of a circle's circumference to its diameter. The English word for this is "pi," which is a Greek letter used in mathematics to denote this constant value approximately equal to 3.14159.

When discussing the character "兀" in a philosophical or literary sense, it might be translated or described differently based on context. For instance, if it's used to convey a sense of being alone or isolated, one might use phrases like "solitary," "lonely," or "isolated." However, these translations do not capture the full essence of what "兀" might represent in certain contexts within Chinese culture and literature.

In summary, while there isn't a direct translation for "兀" into English that captures its full meaning, it can be understood through its various applications and contexts. For mathematical purposes, it corresponds to the term "pi," whereas in other contexts, it may require more descriptive language to convey its meaning accurately.