Er

1. the chemical symbol for erbium, a rare earth element. It has atomic number 68 and an atomic weight of 167.26.
   

1. The termination of many English words, denoting the agent; -- applied either to men or things; as in hater, farmer, heater, grater. At the end of names of places, -er signifies a man of the place; as, Londoner, i. e., London man.
2. A suffix used to form the comparative degree of adjectives and adverbs; as, warmer, sooner, lat(e)er, earl(y)ier.