Dictionaries do not prescribe "real" meanings of words. They describe the senses in which words have been used and are currently used. Meanings are determined by usage, and meanings shift as usage shifts. THe only "rules" language follows are its own organic rules; these too are descriptive rather than prescriptive. Words shift and change meanings over time, and at any given time a word may have multiple meanings. That's just the way it works. Might as well complain that the leaves on your maple tree are the "wrong" shade of green. Language is not something humanity designed, it's something our brains do on their own, to their own rules.