watch ‧ er /ˈwɒtʃə $ ˈwɑːtʃər, ˈwɒː-/ BrE AmE noun [countable]
[ Word Family: noun : ↑ watch , ↑ watcher ; adjective : ↑ watchful , ↑ watchable ; verb : ↑ watch ]
someone who watches someone or something for pleasure or as part of their job
bird/whale/royal etc watcher
Fifteen thousand bird watchers visit annually.
Industry-watchers hailed the takeover as a triumph.