The term 'occurring every 60 minutes' can be summarized by the word 'horal', which is a five-letter word. It is derived from the Latin word 'horologium', which means clock or timepiece. The term 'horal' is used to describe something that happens at regular intervals, such as every hour or every sixty minutes. Therefore, the term 'horal' is an appropriate summary for the phrase 'occurring every 60 minutes'.