Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun er

2 senses of er

Sense 1
erbium, Er, atomic number 68 -- (a trivalent metallic element of the rare earth group; occurs with yttrium)
       => metallic element, metal -- (any of several chemical elements that are usually shiny solids that conduct heat or electricity and can be formed into sheets etc.)

Sense 2
emergency room, ER -- (a room in a hospital or clinic staffed and equipped to provide emergency care to persons requiring immediate medical treatment)
       => hospital room -- (a room in a hospital for the care of patients)