A more thorough explanation:

Term: DI. ET FI.
Definition: DILECTO ET FIDELI, meaning "to my beloved and faithful one".
Example: A love letter addressed to a significant other might begin with "DI. ET FI." to express affection and loyalty.

The term "DI. ET FI." is an abbreviation for the Latin phrase "DILECTO ET FIDELI", which translates to "to my beloved and faithful one". This phrase is often used in personal letters or messages to express love and devotion to someone. For example, a person might begin a love letter to their significant other with "DI. ET FI." to show how much they care about them and how committed they are to the relationship. This abbreviation is a shorthand way of conveying a deep emotional connection and a promise of loyalty.