n. A projecting structure, such as a beam, that is supported at one end and carries a load at the other end or along its length.n. A member, such as a beam, that projects beyond a fulcrum and is supported by a balancing member or a downward force behind the fulcrum.n. A bracket or block supporting a balcony or cornice.v. To construct as or in the manner of a cantilever.verb-intransitive. To extend outward as or in the manner of a cantilever.