Definition of "watcher"

Someone who watches or observes.

1. (chiefly as the final element in compounds) Someone who observes something closely for professional reasons, such as an analyst or pundit.  examples

2. (US politics) A political representative aligned with a candidate sent to observe elections to report on irregularities. A scrutineer.  examples

Someone who keeps vigil.  examples

A guard.  examples

(chiefly historical, Judaism, Christianity) A kind of angel appointed to watch over the human realm, in particular one of those who became fallen angels and begot the Nephilim.