Here's a breakdown of the phrase:
* No: This is the negative command form.
* te: This is the object pronoun "you" (informal, singular).
* dejes: This is the subjunctive form of the verb "dejar" (to let, to allow).
Meaning:
* "Don't let yourself be taken advantage of."
* "Don't let them hurt you."
* "Don't let them control you."
* "Don't let yourself be discouraged."
Example:
* No te dejes llevar por las emociones. (Don't let yourself be carried away by emotions.)
* No te dejes intimidar por ellos. (Don't let them intimidate you.)
The exact meaning of "no te dejes" will depend on the context of the conversation.
Note: You could also see "no te dejes" used with other pronouns (e.g., "no os dejéis" for "don't let yourselves be").