A material that is intentionally added to a pure semiconductor material to increase the population of free holes in that semiconductor, resulting in a net positive charge. A semiconductor that has had acceptor material added to it is called "p-type."
group three elements in the periodic table such as boron aluminum, Al, gallium, Ga, or indium, In, have one less electron in the outer most energy level than silicon, Si. When these atoms are introduced into silicon, an impurity level is created near the valence band. At zero degrees kelvin the impurity level is empty, at room temperature sufficient energy is available to excite electrons from the valence band into the impurity level. Because these Elements introduce impurity levels that accept electrons, they are referred to as acceptors. See also donor.
In a bill of exchange a creditor (the drawer) orders a debtor (the drawee) to pay a certain amount at a certain maturity date. This order is not valid unless it is accepted by the drawee, who is also called the acceptor.