The Collaborative International Dictionary of English v.0.48:
armband \armband\ n. 1. a band worn around arm as identification or to indicate mourning. [WordNet 1.5] 2. a band worn around the upper arm. [WordNet 1.5]WordNet (r) 3.0 (2006):
armband n 1: worn around arm as identification or to indicate mourning 2: a band worn around the upper arm