unreserve

Etymology
From.

Noun

 * 1)  A lack or absence of reserve; frankness; uninhibitedness.
 * 2) * c. 1792–3,, ‘Catharine, or The Bower’, Juvenilia:
 * Kitty, tho' perhaps not authorized to address him with so much familiarity on so short an acquaintance, could not forbear indulging the natural Unreserve and Vivacity of her own Disposition, in speaking to him, as he spoke to her.
 * 1)  A forest that is not set aside as a reserve.

Verb

 * 1)  To undo or cancel a reservation.