1:(adj)Denotes a discussion or confession which is completely honest and completely confidential between all men present, usually 2 and usually inappropriate, sexual, and/or serious.
2:(v) to have such a discussion
Mike: Holy crap dude, this is totally manspeak, but i just banged Carl's sister.
James: WTF she's 17! and hot... I wont say anything, but goddam...
Carl: Mike, can i manspeak to you for a second?