Used to describe the act of drinking alcohol, typically in excess or with the intent of getting wasted. It is a very common term in everyday, informal Argentine speech.
We went to the bar with the guys to mamar for a bit and ended up getting home at some crazy hour.
To soak up or internalize a value, custom, or personality trait from one's upbringing. It refers to naturally incorporating certain behaviors or feelings due to the direct influence of family or the neighborhood during childhood.
That kid is passionate about tango because he mamó it from his grandfather since he was a little boy.