Thesaurus

(n) : a mark or token by which a thing may be known; a visible sign; a character; a distinctive mark or feature; a characteristic quality; a mark, or sign, made to call attention, to point out something to notice, or the like; a sign, or token, proving or giving evidence

(v) : to notice with care; to observe; to remark; to heed; to record in writing; to make a memorandum of