An engorged, swollen, reddish colored (borderline on purple) penis. Typically a penis that is being constructed for rigidness by use of a cock ring or constrictor band.
One may also have a red dogger from popping viagra and jacking off to porn for several hours.
I got a red dogger going on trying to punch his way out of these pants.
I jerked off for three hours yesterday. My sack was dry and left me with a red dogger.
Rachel loves it when I put on my cock harness. My red dogger gets so rigid it could bust a vein.