Mouching means to ask for things or to get things from others without paying for them. It can also mean to wander around without a purpose or to waste time.
Mouching can have a negative feeling because it's not fair to ask for things without giving something back. It can also mean being lazy or not doing what you should be doing.
Examples:
He's always mouching food from his friends.
Stop mouching off of other people!
She's mouching around the house all day.
I caught him mouching candy from the jar.
He's mouching around instead of doing his homework.
Mouching is not a good thing to do.