When a female rides a males hand/arm with enthusiastic vigor, and without remorse. Seldom does the person receiving the jamout participate or even enjoy it.
Mik: Hey Tom does your woman ever Jamm-out?
Tom: Yeah, in fact last night I was rudely awakened by her treating herself to a Jamm-out session on my damn arm.
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."