mathematics (field of study)

question, problem on homework etc. / a question; a matter (of time etc.) / a problem (something that needs to be dealt with); a trouble / an issue; a matter

approximation

to resemble closely

gold bullion

(shogi, sumo, go) A foul or forbidden move / (in general) prohibited move

pyramid / monumental achievement; monumental work

the near future, in a few days, soon

to forbid; to prohibit

to use one's head