The word "乘机" is formed by combining the character "乘", which means to ride or to take advantage of, with the character "机", which means machine or opportunity; this creates a verb-object compound where the action of "乘" acts upon the object "机", resulting in a term that literally means "to ride the machine" or "to seize the opportunity", and which in modern usage specifically denotes taking advantage of a situation or boarding an aircraft.