Give up verb – To give (something) over to the control or possession of another usually under duress. Rat on and give up are semantically related in betray topic. In some cases you can use "Rat on" instead a verb "Give up".
Rat on verb – To give information (as to the authorities) about another's improper or unlawful activities. Give up and rat on are semantically related in betray topic. Sometimes you can use "Give up" instead a verb "Rat on".