Without advance preparation.

synonyms: ad lib, impromptu, spontaneously.

Roget 600: voluntarily etc. adj.; at will, at pleasure; a volonte [Fr.], a discretion; al piacere [It]; ad libitum, ad arbitrium [Lat.]; as one thinks proper, as it seems good to; a beneplacito [It].    of one's won accord, of one's own free will; proprio motu [Lat.], suo motu [Lat.], ex meromotu [Lat.]; out of one's won head; by choice etc. 609; purposely etc. (intentionally) 620; deliberately etc. 611.    ... show more

Roget 639: sufficiently, amply etc. Adj.; full; in abundance etc. n.. with no sparing hand; to one's heart's content, ad libitum, without stint.   

Roget 748: freely etc. adj.; ad libitum etc. (at will) 600.   

Roget 760: by leave, with leave, on leave etc. n.; speciali gratia [It]; under favor of; pace; ad libitum etc. (freely) 748, (at will) 600; by all means etc. (willingly) 602; yes etc. (assent) 488.    ... show more