under-arm \un"der-arm\, a. cricket
   1. done as bowling with the arm not raised above the elbow,
      that is, not swung far out from the body; underhand. cf.
      over-arm and round-arm.
      1913 webster

   2. for use under the arms, specifically in the armpit; as, an
      underarm deodorant.
      pjc
see also:
over-arm round-arm 

underarm
     adj : with hand brought forward and up from below shoulder level;
           "an underhand pitch"; "an underhand stroke" syn: underhand,
            underhanded ant: overhand
     adv : with the hand swung below shoulder level'; "throwing a ball
           underarm" syn: underhand
see also:
underhand underhanded overhand