on; on top; upon; first (of two parts); previous or last (week etc); upper; higher; above; previous; to climb; to go into; above; to go up; to attend (class or university); third tone of putonghua[cedict]
lit. to hone a bull's horn (成语 saw); fig. to waste time on an insoluble or insignificant problem; to bash one's head against a brick wall; a wild goose chase; a blind alley; to split hairs[cedict]
to hold; to contain; to grasp; to take hold of; a handle; particle marking the following noun as a direct object; classifier for objects with handle[cedict]