* Latin is a formal language: It wasn't typically used for casual greetings like "hello". Instead, greetings would be more formal or specific to the situation.
* "Son" in Latin is "filius": While you could use this word, it wouldn't be paired with a greeting in the way we use "hello son".
Here are some options for expressing a similar sentiment:
* "Salve, fili mi!" (Formal): This translates to "Greetings, my son!"
* "Ave, fili mi!" (Formal): This translates to "Hail, my son!"
* "Fili mi, quomodo vales?" (Informal): This translates to "My son, how are you?"
Ultimately, the best way to convey "hello son" in Latin depends on the specific tone and context you want to achieve.