Discretionary

(a.) Left to discretion; unrestrained except by discretion or judgment; as, an ambassador with discretionary powers.

Thesaurus Entries

arbitrary, autonomous, discretional, elective, free, free will, gratuitous, independent, nonmandatory, offered, optional, proffered, self-acting, self-active, self-determined, self-determining, spontaneous, unasked, unbesought, unbidden, uncalled-for, uncoerced, uncompelled, unforced, uninfluenced, uninvited, unpressured, unprompted, unrequested, unrequired, unsolicited, unsought, voluntary, volunteer, willful