A cool cat, very smart, knows his worth and isn't afraid to tell people. Don't mess wit a lark, everybody wants to be a lark.

To have fun, frolic and romp about in a slightly mischievous way.

When someone does a harmless prank.

When you don't have anything particular in mind, but are looking for an entertaining adventure.

To be silly and playful.

something done merely out of enjoyment or appreciation of the activity.

When one says they will be in a certain place at a certain time and then are (a) very late leaving you there on your own for ages or (b) text you saying they will be there soon leaving you there on your own for ages or (c) text you saying they wont be out at all after you have been there on your own for ages.