Now what is dinner?The senses 1&2 are contradicting each other!
dinner ['d?n?]
n
1. (Cookery) a meal taken in the evening
2. (Cookery) a meal taken at midday, esp when it is the main meal of the day; lunch
3. (Cookery)
a. a formal evening meal, as of a club, society, etc.
b. a public banquet in honour of someone or something
4. (Cookery) a complete meal at a fixed price in a restaurant; table d'hôte
5. (Cookery) (modifier) of, relating to, or used at dinner dinner platedinner tabledinner hour
do like a dinner(usually passive)Australinformal to do for, overpower, or outdo
[from Old French disner; see dine]
http://www.thefreedictionary.com/_/misc/HarperCollinsProducts.aspx?English© HarperCollins Publishers 1991, 1994, 1998, 2000, 2003
They are not contradictory; they are two different meanings for the word, just as with other words such as cleave, overlook, presently, sanction, etc.
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