from
The Collaborative International Dictionary of English v.0.48
Shampoo \Sham*poo"\, v. t. [imp. & p. p. {Shampooed}; p. pr. &
vb. n. {Shampooing}.] [Hind. ch[=a]mpn[=a] to press, to
squeeze.] [Writing also {champoo}.]
1. To press or knead the whole surface of the body of (a
person), and at the same time to stretch the limbs and
joints, in connection with the hot bath.
[1913 Webster]
2. To wash throughly and rub the head of (a person), with the
fingers, using either soap, or a soapy preparation, for
the more thorough cleansing.
[1913 Webster]