It means "remember" or "take care".
Here are some examples:
* "Ingat ka!" (Tandaan mo!) - Take care!
* "Ingat mo ti anakmo!" (Alagaden mo ti anakmo!) - Take care of your child!
* "Ingatmo ti sasayen mo!" (Tandaan mo ti sasayen mo!) - Remember what you learned!
Note: The word "ingat" is also sometimes used in Ilocano, but it's more commonly used in Tagalog.