助教授
じょきょうじゅ · jokyouju · JLPT N2 · noun
assistant professor
🎓 助 (help) + 教授 (professor) = assistant professor, a professor who helps
助 means help or assist, and 教授 means professor, so the compound is a professor's helper. Since 2007 Japan uses 准教授 for this rank; 助教授 is the older term.
教 — 老 (filial son being taught) + 攵 (hand with stick)
教 originally depicted an adult holding a stick or rod (攵) instructing a child, often shown with the element 爻 (lessons/counting) above 子 (child). It is a classic associative compound meaning 'to teach' or 'to instruct,' with the right side suggesting discipline and guidance. The modern meanings 'teach, religion, doctrine' all extend from this image of formal instruction.