It means that person likes you, or doesn't want you to know something.
If he looks at you and then down at your lips he wants to kiss you
Depends where he's looking, might just find eye contact awkward
it means she doesn't want to make eye contact with you or that she is shy and that she likes you
When a person looks up and then to the left and right, they are just checking out their surroundings. They may be unsure of their surroundings.
It could indicate that the person is observing you from a distance but feels uncomfortable or shy when closer to you, which is why they avoid making direct eye contact. They may be interested in you but unsure of how to approach you.
she does not want to look at you
Then you are being prejudice.
no improprer or allowable contact with a person or object
It means you should contact the police.
They are sizing you up.
a description to how a person looks also describing what that person is wearing
When a guy looks at you up and down, it could indicate that he is checking you out or showing interest in you physically. However, it's important to consider the context and his body language to determine if it's done respectfully or inappropriately.