A Bronx teacher’s lesson was lost in translation when she was fired for calling a student “negro” when she was just teaching her class the Spanish word for “black,” her lawsuit claims.

Petrona Smith, 65, was booted from bilingual PS 211 in March 2012 after a seventh-grader reported the alleged insult. The boy’s parents have since said he lied.

The city Law Department said, “We’ve received the papers and will review them.”