n.
     - a circumstance, fact, or influence that contributes to a result. ▸Biology  a gene that determines a hereditary characteristic. 
- Mathematics  a number or quantity that when multiplied with another produces a given number or expression. ▸a number or algebraic expression by which another is exactly divisible. 
- a level on a scale of measurement:![]()  a protection factor of 15. 
- Physiology  any of a number of substances in the blood which are involved in coagulation.
- a business agent. ▸a company that buys a manufacturer's invoices at a discount and takes responsibility for collecting the payments due on them. ▸Scottish a land agent or steward. 
v.
   - 
(factor something in/out)
 include (or exclude) something as a relevant element when making a decision.
- Mathematics  another term for factorize.
- sell (one's receivable debts) to a factor.
Derivative
  
  Etymology
  ME (meaning ‘doer’, also in the Scots sense ‘agent’): from Fr. facteur or L. factor, from fact-, facere ‘do’.