To use; to have in service; to cause to be engaged in
   doing something; -- often followed by in, about, on, or upon, and
   sometimes by to; as: (a) To make use of, as an instrument, a means, a
   material, etc., for a specific purpose; to apply; as, to employ the pen
   in writing, bricks in building, words and phrases in speaking; to
   employ the mind; to employ one's energies.