nouns
a person who works at a specific occupation
"he is a good worker"
is a type of (narrower)
a human being
"there was too much for one person to do"
a member of the working class (not necessarily employed)
"workers of the world--unite!"
sterile member of a colony of social insects that forages for food and cares for the larvae
is a type of (narrower)
small air-breathing arthropod
a person who acts and gets things done
"he's a principal actor in this affair"; "when you want something done get a doer"; "he's a miracle worker"