Section 87PP. For the purposes of sections eighty-seven PP to eighty-seven DDD, inclusive, the following words and phrases, unless the context otherwise requires, shall have the following meanings:—

''Board'', the board of registration of real estate brokers and salesmen.

''Non-resident'' shall include and be deemed to apply to an individual whose principal place of abode is without the commonwealth and to a corporation, society, association or partnership, organized, formed or existing under the laws of another state and which does not maintain a usual place of business within the commonwealth.

''Real estate'', any and every estate or interest in land and the improvements thereon, whether corporeal or incorporeal, whether freehold or non-freehold, and whether or not said land is situated within the commonwealth.

''Real estate broker'', hereinafter referred to as broker, any person who for another person and for a fee, commission or other valuable consideration, or with the intention or in the expectation or upon the promise of receiving or collecting a fee, commission or other valuable consideration, does any of the following:—sells, exchanges, purchases, rents or leases, or negotiates, or offers, attempts or agrees to negotiate the sale, exchange, purchase, rental or leasing of any real estate, or lists or offers, attempts or agrees to list any real estate, or buys or offers to buy, sells or offers to sell or otherwise deals in options on real estate, or advertises or holds himself out as engaged in the business of selling, exchanging, purchasing, renting or leasing real estate, or assists or directs in the procuring of prospects or the negotiation or completion of any agreement or transaction which results or is intended to result in the sale, exchange, purchase, leasing or renting of any real estate.

''Real estate salesman'', hereinafter referred to as salesman, an individual who performs any act or engages in any transaction included in the foregoing definition of a broker, except the completing of the negotiation of any agreement or transaction which results or is intended to result in the sale, exchange, purchase, renting or leasing of any real estate.