WordNet sense 1 (the officer who presides at the meetings of an organization):

chairman, chairperson, chairwoman, president

WordNet sense 2 (an instrument of execution by electrocution; resembles an ordinary seat for one person):

electric chair, hot seat, death chair

WordNet sense 3 (preside over):

lead, moderate, lead, moderate, lead

WordNet sense 4 (the position of professor):

professorship