jammin like salmon
When someone is having such a good time (i.e. drinking, dancing, etc.) that the only way he/she can describe it is with rhyme; a derivative of the nonsensical "out like trout"
Mary: "How was the party last night?"
Brad: "It was so much fun. We were jammin like salmon until the cops came. And then we were out like trout."
Brad: "It was so much fun. We were jammin like salmon until the cops came. And then we were out like trout."