Meaning: someone who is excluded from or is not a member of a group
In these Wessex nooks the busy outsider's ancient times are only old; his old times are still new; his present is futurity.
This fellow Grant is practically an outsider; he doesn't belong in Oakdale. He's a presuming cub, too--always pushing himself forward.
She grew purple in the face with indignation and astonishment, that a casual outsider should venture to address her; so much so, indeed, that for a second I almost regretted my well-meant interposition.