What does this 3 bet Mean?

[RickA]

Hi all

I was playing .5/1 at GC. Loose passive table with 1 LAG on my left. I'm UTG with AKo. I raise LAG 3 bets, I call. What hands should I put him on? I figured him to have JJ-AA or AK AQo with AQ being a stretch. He wouldn't 3 bet with high suited connectors because he wouldn't want to limit the field. With him being such an aggressive player how much should I respect his raise? Flop was 9c Kh 8c. I bet he raised, I 3 bet, he capped. Am I beat for sure?

Thanks
RickA