a wise person; a philosopher
At the end of a lifetime of intense intellectual and spiritual activity, he was revered as a sage by the nation, yet he always claimed that he was really no more intelligent than the average person.
sapere (to have a taste, have good taste, be wise) (Latin)
who has "usage"? of course sage person. you can use his/her experiences, hence sage has usage If one knows the meaning of saga, that is any legend, one can easily remember sage. A saga will be a wise, sensible person.