1. a public announcement appearing in print, broadcast, or electronic media that is designed to bring individuals’ attention to a particular item or service in order to encourage the purchase, consumption, or increased use of that item or service. See also advertising psychology; advertising research.

2. in animal behavior, a signal or display that emphasizes or calls attention to the organism producing it. For example, a male bird defending a territory might use advertisement in the form of bright coloration and conspicuous song both to attract mates and to deter competing males. Compare camouflage.