Merriam-Webster's Collegiate® Dictionary, 11th Edition
LABEL
I. noun
Etymology: Middle English, from Anglo-French labelle
Date: 14th century
band , fillet , a heraldic charge that consists of a narrow horizontal band with usually three pendants,
3. a slip (as of paper or cloth) inscribed and affixed to something for identification or description, written or printed matter accompanying an article to furnish identification or other information, a descriptive or identifying word or phrase: as, epithet , a word or phrase used with a dictionary definition to provide additional information, a usually radioactive isotope used in labeling, an adhesive stamp (as for postage or revenue),
5. a. a brand of commercial recordings issued under a usually trademarked name, a recording so issued, a company issuing such recordings, the brand name of a retail store selling clothing, a clothing manufacturer, or a fashion designer,
II. transitive verb (labeled or labelled; labeling or labelling)
Date: 1601
1. to affix a label to, to describe or designate with or as if with a label,
2. to distinguish (an element or atom) by using an isotope distinctive in some manner (as in mass or radioactivity), to distinguish (as a compound or cell) by introducing a traceable constituent (as a dye or labeled atom), labelable adjective labeler noun