https://idioms.thefreedictionary.com/street+smart
A couple of commentaries on the basic definition:
#1
Street Smart is the ability/ skill to come out of every situation with the favorable outcome. It's a combined knowledge of prior life experiences and natural logic. These people are not naive and cannot be easily manipulated.
Someone who's street smart tend to :
knows what's going on in the world around them - they detect BS very quickly
Know the various types of people that exist and how to deal with each one and know how to act around them.
Know how to get out of sticky situations
knows how to make sound decisions that will benefit him/her
To have common sense at level 9000.
Knows how not to get screwed over or be taken advantage of. ( if anything they take advantage of you )
Be open minded, listen and understand the order of everyday things.
Most importantly they know how to read between the lines and see things for exactly what they are.
Normally it has to do with shady stuff knowledge:
Knowing where and who in the neighborhood is sexually exploitable;
Knowing where and who in the neighborhood sells drugs/weapons;
Knowing which places are easy to steal from;
Knowing the extend to which someone has criminal power in the city (for example, some gangsters have connection in the taxi industry for drug transport, some restaurants are frauds that are only used to spend illegal money, sex clubs, bars, beauty shops, etc…);
Knowing where and who are the clients for the different illegals services (sex, drugs, weapons, etc…);
Knowing where and how to go if police is after you;
Knowing how to use multiple cellphones for different reasons;
Knowing how to intimidate people and how to respond to intimidation;
Knowing who is corrupted (police officers, academics, politicians, etc…);
Knowing that no ones really has your back and that you are better off alone.