From The Collaborative International Dictionary of English v.0.48:
Tee \Tee\, n.
1. A short piece of pipe having a lateral outlet, used to
connect a line of pipe with a pipe at a right angle with
the line; -- so called because it resembles the letter T
in shape.
[1913 Webster]
2. The letter T, t; also, something shaped like, or
resembling in form, the letter T.
[Webster 1913 Suppl.]
From The Collaborative International Dictionary of English v.0.48:
Tee \Tee\, v. t. [imp. & p. p. Teed; p. pr. & vb. n.
Teeing.] (Golf)
To place (the ball) on a tee; also called to tee up.
[Webster 1913 Suppl.]
From The Collaborative International Dictionary of English v.0.48:
Tee \Tee\, n. [Cf. Icel. tj[=a] to show, mark.]
(a) The mark aimed at in curling and in quoits.
(b) The nodule of earth, or a short peg stuck into the
ground, from which the ball is struck at the beginning of
play for each hole in golf.
[1913 Webster +PJC]