functionally related business
(4) Functionally related business The term “functionally related business” means— (A) a trade or business which is not an unrelated trade or business (as defined in section 513 ), or (B) an activity which is carried on within a larger aggregate of similar activities or within a larger complex of other endeavors which is related (aside from the need of the organization for income or funds or the use it makes of the profits derived) to the exempt purposes of the organization.