For purposes of this article, the following terms shall have the meanings indicated:
Any knife consisting of a razor blade, retractable, nonretractable or detachable in segments, attached to or contained within a plastic or metal housing, including utility knives, snap-off knives and box carton cutters.
Any natural person, corporation, partnership, firm, organization or other legal entity.
The buildings, grounds or facilities or any portion thereof owned, occupied by or under the custody or control of public or private institutions for the primary purpose of providing educational instruction to students at or below the 12th grade level and any vehicles owned, operated or leased by such institutions which are used to transport such students or the personnel of such institutions.