From WordNet (r) 3.0 (2006) [wn]:
necklace
n 1: jewelry consisting of a cord or chain (often bearing gems)
worn about the neck as an ornament (especially by women)
From The Collaborative International Dictionary of English v.0.48 [gcide]:
necklace \neck"lace\ (?; 48), n.
1. A string of beads, etc., or any continuous band or chain,
worn around the neck as an ornament.
[1913 Webster]
2. (Naut.) A rope or chain fitted around the masthead to hold
hanging blocks for jibs and stays.
[1913 Webster]