Employ

1. To inclose; to infold.
2. 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.
1. To occupy; as, to employ time in study.
2. To have or keep at work; to give employment or occupation to; to intrust with some duty or behest; as, to employ a hundred workmen; to employ an envoy.
To employ one's self ,
to apply or devote one's time and attention; to busy one's self.

1. That which engages or occupies a person; fixed or regular service or business; employment.
   
In one's employ ,
in one's service.