The Collaborative International Dictionary of English v.0.48:

Teen \Teen\, n. [OE. tene, AS. te['o]na reproach, wrong, fr.
   te['o]n to accuse; akin to G. zeihen, Goth. gateihan to tell,
   announce, L. dicere to say. See Token.]
   Grief; sorrow; affiction; pain. [Archaic] --Chaucer. Spenser.
   [1913 Webster]

         With public toil and private teen
         Thou sank'st alone.                      --M. Arnold.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Teen \Teen\, v. t. [AS. te['o]nian, t?nan, to slander, vex.
   [root]64. See Teen, n.]
   To excite; to provoke; to vex; to affict; to injure. [Obs.]
   --Piers Plowman.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Teen \Teen\, v. t. [See Tine to shut.]
   To hedge or fence in; to inclose. [Prov. Eng.] --Halliwell.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Teen \Teen\, n.
   a teenager.
   [PJC]

WordNet (r) 3.0 (2006):

teen
    adj 1: being of the age 13 through 19; "teenage mothers"; "the
           teen years" [syn: adolescent, teen, teenage,
           teenaged]
    n 1: a juvenile between the onset of puberty and maturity [syn:
         adolescent, stripling, teenager, teen]