The term 'PERTAINING TO HEARING' can be summarized by two crossword solutions: OTIC and AURAL. OTIC is a four-letter word derived from the Greek word 'ōtikos, ' meaning 'pertaining to the ear.' AURAL is a five-letter word derived from the Latin word 'auralis, ' meaning 'pertaining to the ear or hearing.' Both words refer to the sense of hearing, and are often used in medical contexts to describe conditions related to the ear or hearing.