To outsmell someone means to have a stronger or more noticeable smell than them.
Outsmelling someone can be a good thing if you like the smell, but it can be a bad thing if you don't like the smell.
Examples:
My flowers outsmell your flowers.
The pie outsmells the soup.
The cake outsmells the bread.
I outsmell my brother after I take a bath.
My dog outsmells all the other dogs in the park.
The flowers outsmell everything else in the garden.