teacher who took the job for lack of better options; unmotivated teacher
Derogatory slang for a teacher who entered the profession not out of passion but because they couldn't find anything else to do. Often implies low motivation or competence.
That teacher is clearly just someone who became a teacher for lack of anything better, don't you think?
It's a shame for students to be taught by an unmotivated teacher.
Compound of でも (or something) and しか (only), suggesting a person who became a teacher merely because they could, not out of genuine desire. The exact origin is uncertain, but it reflects a cynical view of the teaching profession.