\Punc*til"ious\ (-y[u^]s), a. [Cf. It. puntiglioso, Sp. puntilloso.] Attentive to punctilio; very nice or exact in the forms of behavior, etiquette, or mutual intercourse; precise; exact in the smallest particulars. ``A punctilious observance of divine laws.'' --Rogers. ``Very punctilious copies of any letters.'' --The Nation. Punctilious in the simple and intelligible instances of common life. --I. Taylor. -- {Punc*til"ious*ly}, adv. -- {Punc*til"ious*ness}, n.