say it: TEE-chur
teacher is a noun meaning "a person whose occupation is teaching". It carries 2 recorded senses.
a person whose occupation is teaching
a personified abstraction that teaches
“books were his teachers”
“experience is a demanding teacher”
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for teacher come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.