Adam Rawnsley explains the non-meaning behind "Operation Odyssey Dawn":
Each command within the vast Defense Department apparatus is given a series of two-letter groupings that they can use for their operations’ two-word sobriquets. Under the system, the U.S. Africa Command, nominally in charge of the Libya strikes, was given three sets of words that it could begin the operation with.
“These words begin between the letters JF-JZ, NS-NZ and OA-OF, and those three groups give about 60 some odd words,” explains Africom spokesman Eric Elliott. “So, the folks who were responsible for naming this went through and they had done recent activities with NS and they went to O.”
Using the O series of letters, Africom officials picked out “Odyssey” for the first word. The second word is picked “as random as possible because that’s the goal of these operational names,” says Elliot. Africom pulled out “Dawn” for its second word and the resulting combination, “Odyssey Dawn,” is devoid of any intended meaning, Elliott insists.
Meanwhile, the Army Rumour Service - an unofficial UK military online forum, among others, have been debating the term Operation Ellamy, the British operational name. And the reasoning behind the naming of Canadian Operation MOBILE is also unclear.
The French operation is named Operation Harmattan. The Harmattan, according to Wikipedia, "is a dry and dusty West African trade wind. It blows south from the Sahara into the Gulf of Guinea".