she who explains, elucidates, clarifies, etc.

a woman who presents the programmemes on radio or television.

she who sees, perceives, notices, etc.

explaining; elucidating; clarifying.

he who sees, percevies, notices, etc.

the act of seeing, perceiving or noticing; he who explains, elucidates, clarifies, etc.

the act or process of explaining or elucidating.

a man who presents the programmemes on radio or television.

(math.) a number or algebraic symbol prefixed as a multiplier to a variable or unknown quantity (Ex.: x in x(a-b)).