Being the first in time or in history. / Of greatest importance; primary.

A primal cut (of meat).

(intransitive) To take part in primal therapy.

(psychology) A consequence, such as food or water, that fulfills a primary, unlearned drive, such as hunger or thirst, and thereby reinforces a behavior without dependence on prior learning.

The minimum price of a good or service that would result in zero quantity being demanded.

(publishing) No longer offered for sale by a publisher; no longer on the firsthand market.

(number theory) A factor of a given integer which is also a prime number.

(transitive) to reduce an integer to its set of prime factors.

(finance) The list price or sticker price of an item; the price without any discounts or incentives.

most important