The art and practice of cockblocking, generally in reference to intentional, rather than inadvertent, acts of cockblocking. However, this term can also be used to describe the tendencies of a person who possesses a certain oblivious demeanor that lends well to unintentional, albeit frequent, cockblocking activity.
This has to be at least the tenth time Stu has destroyed my chances. That guy's penchant for cockblockery knows no bounds.
A male who unwittingly(out of ignorance) or purposefully(out of jealousy) prevents another male from engaging in debauchery with members of the female sex. Females can also cockblock, but the true essence of the word lies in the metaphor of the penis used figuratively as an impediment which thwarts any possible chances of scoring with members of the opposite sex.
friend # 1 interrupting friend # 2, who is conversing with a female at a local bar.
"Hey i don't mean to interrupt, but did you ever get the results of those STD tests that you took?