schoolmarm

noun Older Use.

1. a female schoolteacher, especially of the old-time country school type, popularly held to be strict and priggish.

noun informal

1. a woman schoolteacher, esp when considered to be prim, prudish, or old-fashioned
2. British any woman considered to be prim, prudish, or old-fashioned

n.also school-marm, “female school teacher,” 1834, American English colloquial, in countrified humor writing of “Major Jack Downing” of Maine (Seba Smith); variant of school-ma’am (1828), American English, from school (n.1) + ma’am. See R. Used figuratively from 1887 in reference to patronizing and priggish instruction.