The unusually flaccid penis a male develops after the consumption of many drugs. This is typically accompanied by (1)frequent trips that the toilet that result in unsuccessful attempts to urinate and (2) inability to arrive at an erection despite being extraordinarily horny (see also blue balls)
A similar phenomenon occurs in females called crack cunt.
"I have crack cock so bad I stood at the urinal for five minutes and only pissed a single drop."
Spilling your beans nonstop to any and everyone who will listen. This especially applies when you're cracked out or tweaked on drugs and feel the need to share every random thought that crosses your mind.