The action or fact of aiming off in order to hit a target, travel in the desired direction, etc.; the amount by which this is judged to be necessary in a particular instance.
Origin
1930s. From aim + off, after to aim off.
Definition of aim-off in US English:
aim-off
nounˈeɪmɒf
The action or fact of aiming off in order to hit a target, travel in the desired direction, etc.; the amount by which this is judged to be necessary in a particular instance.