n. (Law) One who rents a tenement, or land, etc., of one who is also a tenant; an undertenant. [ 1913 Webster ]

v. t. [ imp. & p. p. Subtended; p. pr. & vb. n. Subtending. ] [ L. subtendere; sub under + tendere to stretch, extend. See Tend. ] To extend under, or be opposed to; as, the line of a triangle which subtends the right angle; the chord subtends an arc. [ 1913 Webster ]

n. [ L. subtendere, subtentum. See Subtend, Tense, a. ] (Geom.) A line subtending, or stretching across; a chord; as, the subtense of an arc. [ 1913 Webster ]