The term given to the male genitalia after repetitive, extensive use, leaving it raw and tender much like sashimi, or sushi. It is thus rendered incapable to perform it's erectile duties.
To expose just your dick to an unsuspecting person in a public or semi public place. Generally done by exposing the penis through the zipper of shorts or pants or allowing the cock to hang out the leg hole of a pair of shorts. More often than not, when a man is dickflashing, he pretends not to know he is exposing himself to his voyeur, so as to prevent any trouble and allow the person looking to enjoy viewing his organ in secret.