school·marm 
(sklmärm′) also school·ma'am (-mäm′, -măm′)
(sklmärm′) also school·ma'am (-mäm′, -măm′)n.
A woman teacher, especially one who is regarded as strict or old-fashioned.
[SCHOOL1 + dialectal marm (variant of MA'AM).]
schoolmarm′ish adj.