Forgot to mention that I measured thrust the other day. This is a 3.7V motor at 40,000 rpm.
Nontechnical way to describe thrust is the amount of force (unit grams) it takes to move the mass (blimp gondola) out of the way.
The real definition is the perpendicular force to the load measured in newtons, or the amount needed to accelerate 1 kilogram of mass at the rate of 1 meter per second per second. Source: wikipedia