Words used in the present tense include the future; the singular number includes the plural, and the plural the singular. The word "lot" includes the word "plot." The word "building" includes the word "structure." The term "such as," where used herein, shall be considered as introducing a typical or illustrative, rather than an entirely exclusive or inclusive, designation of permitted or prohibited uses, activities, establishments or structures. The words "zone" and "district" are synonymous.