7.—(1) A person shall be entitled to be registered as a presidential elector in a constituency if he has reached the age of eighteen years and if he was, on the qualifying date—

( a ) a citizen of Ireland, and

( b ) ordinarily resident in that constituency.

(2) For the purposes of—

(i) the Presidential Elections Acts, 1937 to 1992,

(ii) the Referendum Acts, 1942 to 1992, and

(iii) this Act,

"presidential elector" means a person entitled to vote at an election of a person to the office of President of Ireland.

(3) In the Presidential Elections Acts, 1937 to 1992 "elector", when used alone, means a person described in subsection (1).