discretion

Discretion is the quality of being careful with regard to one's actions and speech. See how you translated this in Proverbs 1:4.

your lips may protect knowledge

Here the word "lips" represents the person who speaks. The writer speaks of a person being careful only to say what is true as if the person's lips were protecting knowledge. AT: "you will speak only what is true" (See: rc://en/ta/man/translate/figs-synecdoche and rc://en/ta/man/translate/figs-metaphor)