The translation of "【函義】" into English is **"meaning of the letter"** or **"implication of the letter"**, depending on the context.

If referring to the literal meaning of a written letter (信函), it can be translated as:
- **"Meaning of the letter"**
- **"Content of the letter"**

If referring to a deeper implication or connotation (隱含的意義), it can be:
- **"Implication of the letter"**
- **"Underlying meaning"**

Could you provide more context so I can refine the translation further?