business end

Short definition from Wiktionary

Noun

1. 1
   The part of a day, event, or place (such as a city or district) used for business activities.
2. 2
   The part of an object (chiefly a tool or weapon) that is physically used for its operation, rather than some other part such as the part by which it is held.
3. 3
   The part of an activity, period of time, etc., which is most important and produces the significant result.