A heterosexual male who has non-sexual, yet very close, personal relationships with lesbians. These relationships may be sexually non-threatening, and are often based on searching out other women for sexual relationships.
My brother's a lezbro because he is always hanging out with lesbians - he says it's because they have similar tastes in women!
A heterosexual man who enjoys the company of the gay female community. This is basically the male version of a "Fag Hag," and a "Lez Bro" is comfortable going to gay bars, attending lesbian events, and watching "Ellen."
John is a straight guy who lives in Dupont Circle in Washington DC. John likes going out with his lesbian neighbors better than he likes going out with his law-school buddies. John is a true Lez Bro.