I was wondering the same thing. I do not think any of these are what he meant:
Acronym Definition
AGW Access Gateway
AGW Accident Generated Water
AGW Actual Gold Weight
AGW Actual Gross Weight
AGW All Going Well
AGW Allowable Gross Weight
AGW Alt.Games.Warbirds (forum)
AGW Anganwadi Worker (India)
AGW Anthropogenic Global Warming
AGW Application Gateway (telecom)
AGW Art Gallery of Windsor (Ontario, Canada)
AGW Atmospheric Gravity Waves
AGW Automatic Girth Welder
AGW Autonomous Guided Weapon
AGW Audio Gateway
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Who knows, maybe he actually was talking about Atmospheric Gravity Waves.