(n) A person or group of people laughed at for actions that they take, despite not trying to be funny. They may try to take themselves seriously, but are often “milked” for laughs with or without their knowledge
Teams like the browns, Oilers, redskins and grizzlies are some of the greatest lolcows in over the past decade in the world of sports
A lolcow is a person you get extensive laughs from, who doesn't know they are being made fun of. They can often think they are admired for what they are doing, but secretly are being laughed at constantly.
A phenomena, usually observed on forums and/or imageboards. A person, most often someone who tries to look exceedingly knowledgeable in the topic discussed, is being flamed/trolled to the point where they can no longer present "sane" arguments that will "fit their level", but yet are too proud to just quit.
This produces a considerable amount of lolz and win, for which the said person can be "milked" until they finally give up. Or drop dead. Hence the name.