mid-14c., distribucioun, "act of dividing or parceling out," from Old French distribution (13c.) and directly from Latin distributionem (nominative distributio) "a division, distribution," noun of action from past-participle stem of distribuere "to divide, deal out in portions," from dis- "individually" (see dis-) + tribuere "to pay, assign, grant," also "allot among the tribes or to a tribe," from tribus (see tribe).
Meaning "that which is distributed or apportioned" is from late 14c. Sense of "act of spreading out as over a surface" is from 1580s. Related: Distributional (1804).