Fac"tor (?), n. [L. factor a doer: cf. F. facteur a factor. See Fact.] 1. (Law) One who transacts business for another; an agent; a substitute; especially, a mercantile agent who buys and sells goods and transacts business for others in commission; a commission merchant or consignee. He may be a home factor or a foreign factor. He may buy and sell in his own name, and he is intrusted with the possession and control of the goods; and in these respects he differs from a broker. Story. Wharton.

My factor sends me word, a merchant's fled
That owes me for a hundred tun of wine.

2. A steward or bailiff of an estate. [Scot.] Sir W. Scott.

3. (Math.) One of the elements or quantities which, when multiplied together, form a product.

4. One of the elements, circumstances, or influences which contribute to produce a result; a constituent.

The materal and dynamical factors of nutrition.

Fac"tor, v. t. [imp. & p. p. Factored (-t?rd); p. pr. & vb. n. Factoring.] (Mach.) To resolve (a quantity) into its factors.

• doer, maker; a person who does things for another person or organization
        The factor of the trading post bought the furs.
  
• an integral part
       The greatest factor in the decision was the need for public transportation.
       The economy was a factor in this year's budget figures.
  
• (Mathematics) a whole number by which another whole number can be divided with no remainder
       Three is a factor of 12.
  
• find all of a number's factors (the numbers which divide into the first number evenly), often used in encryption
  
  Latin
• doer, maker; one who or which does or makes something