ad lib(r = adv.all) ad libitum, impromptu, spontaneously - without advance preparation; "he spoke ad lib"

ad lib, v., adj., adv., & n.
--v.intr. (ad libbed, ad libbing) speak or perform without formal preparation; improvise.
--adj. improvised.
--adv. as one pleases, to any desired extent.
--n. something spoken or played extempore.

Etymology:
abbr. of AD LIBITUM

VB  be unprepared, want preparation, lack preparation, lie fallow, s'embarquer sans biscuits, live from hand to mouth, dismantle, undress, extemporize, improvise, ad lib.

N  nonpreparation, non-preparation, absence of preparation, want of preparation, inculture, inconcoction, improvidence, immaturity, crudity, rawness, abortion, disqualification, nature, state of nature, virgin soil, unweeded garden, neglect, rough copy, germ, raw material, improvisation, unprepared (prepare), without preparation, incomplete, rudimental, embryonic, abortive, immature, unripe, kachcha, raw, green, crude, coarse, rough cast, rough hewn, in the rough, unhewn, unformed, unfashioned, unwrought, unlabored, unblown, uncooked, unboiled, unconcocted, unpolished, unhatched, unfledged, unnurtured, unlicked, untaught, uneducated, uncultivated, untrained, untutored, undrilled, unexercised, deckle- edged, precocious, premature, undigested, indigested, unmellowed, unseasoned, unleavened, unrehearsed, unscripted, extemporaneous, improvised, spontaneous, ad lib, ad libitem, fallow, unsown, untilled, natural, in a state of nature, undressed, in dishabille, en deshabille, unqualified, disqualified, unfitted, ill-digested, unbegun, unready, unarranged, unorganized, unfurnished, unprovided, unequipped, untrimmed, out of gear, out of order, dismantled, shiftless, improvident, unthrifty, thriftless, thoughtless, unguarded, happy-go- lucky, caught napping, unpremeditated, extempore.

ad, ad agency, ad blitz, ad campaign, ad captandum, ad hoc, ad hominem, ad infinitum, ad interim, ad libitum, ad nauseam, ad val, ad valorem, ad valorem tax, classified ad, gay lib, lib, newspaper ad, reductio ad absurdum, subpoena ad testificandum, terminus ad quem, want ad, women's lib