A necklace worn high on the neck is a choker[?].
In BDSM, a necklace can serve as an elegant kind of slave collar[?].
See also:
... great explorers (in alphabetic order by surname): Table of contents 1 A 2 B 3 C 4 D 5 E 6 F 7 G 8 H 9 I 10 J 11 L 12 M 13 N 14 O 15 ...