The definition of besides mean in addition to or furthermore.
(adverb)Besides is defined as in addition to, or except for.
(preposition)See besides in Webster's New World College Dictionary
adverb
Origin: ME < beside + adv. gen. -(e)s
See besides in American Heritage Dictionary 4
adverb
Origin:
Origin: Middle English
Origin: : biside, at the side; see beside
Origin: + -es, adv. suff.; see -s3
. Usage Note: Some critics argue that beside and besides should be kept distinct when they are used as prepositions. According to that argument, beside is used only to mean “at the side of,” as in There was no one in the seat beside me. For the meanings “in addition to” and “except for” besides should be used: Besides replacing the back stairs, she fixed the broken banister. No one besides Smitty would say a thing like that. But this distinction is often ignored, even by widely respected writers. While it is true that besides can never mean “at the side of,” beside regularly appears in print in place of besides. Using beside in this way can be ambiguous, however; the sentence There was no one beside him at the table could mean that he had the table to himself or that the seats next to him were not occupied. See Usage Note at together.Learn more about besides