Addressed to a teacher, or to a person who is temporarily acting like a teacher. The scene described by Laurie Lee in Cider with Rosie is concerned with village school life in the early 1920s: Each morning was war without declaration; no one knew who would catch it next. We stood to attention, half-crippled in our desks, till Miss B walked in, whacked the walls with a ruler, and fixed us with her squinting eye. ‘Good a-morning, children!’ ‘Good morning, Teacher!’ Most modern teachers probably prefer to be addressed by name in such a situation, and few try to rule by fear these days.
   In The Liberty Man, by Gillian Freeman, ‘teacher’ becomes a friendly vocative when used by a young man to his former teacher. They are no longer in a teacher-student relationship, something the young man finds difficult to adjust to.
   Looking for Mr Goodbar, by Judith Rossner, has a man who addresses his lover, who happens to be a teacher, as ‘Teach’. Once again there is novelty in the fact that his relationship with a teacher is so different from those he knew as a child.
   In Georgy Girl, by Margaret Forster, a girl is asking a man questions about himself and his career. ‘Why did you work there in the first place?’ she asks. ‘Please teacher,’ he says, ‘because I had to earn my living.’ An interrog ation situation such as this often causes a vocative such as ‘my lord’, ‘your lordship’. ‘Mr District Attorney’, or some other court-room term to be used. ‘Teacher’ is more unusual in such a context, but reflects the man’s feelings about being put into, a subordinate position by the questioning.
   A character in Pygmalion, by George Bernard Shaw, says to Higgins: ‘You come from ‘Anwell. Go back there.’ Higgins, meaning to be helpful, points out that the place-name is ‘Hanwell’. Thank you, teacher,’ says the man who has been corrected, with a great deal of sarcasm.
   In some instances ‘sir’ or ‘miss’, the normal terms by which teachers are addressed, may be used in these teacher-like situations, but only if the speaker is pretending to adopt pupil status. Simple professional use of ‘teacher’ by someone other than a student occurs in Jane Eyre, by Charlotte Brontë. The patron of a charity school is paying a visit and tells the assembled staff: ‘Teachers, you must watch her [i.e. Jane].’

A dictionary of epithets and terms of address . . 2015.