1 in addition, additionally, also; further, furthermore, moreover, as well, too; to boot, on top of everything else, into the bargain:
Maria is our choice for the post and, besides, she's the only qualified person available. On their anniversary he gave her a diamond ring and a sapphire brooch besides.
2 over and above, above and beyond, in addition to, additionally to, as well as; aside from, barring, excepting, except for, excluding, exclusive of, not counting or including, beyond, apart from, other than:
St Paul became acquainted with many Christians besides his converts.