Of, pertaining, espousing, or involving actions which include both a merkin and a moustache ride in interchangeable forms. Generally used as a socially acceptable euphemism made in reference to one's wardrobe.
"My, you are looking quite flannerish today, it must be your leopard-print thong and paisley vest."
A manly man, who does not take crap from the opposite sex. He does not go to baby showers, he stays at home on Sundays for football, and does not show weakness to his wife in the presence of his male friends
Pretty self-explanatory. A flannelgay is an endearing term used to describe a bro who digs wearing flannel and doesn't hide his appreciation of other bros who also like wearing flannel shirts.
Oh dude, I had no idea you also loved wearing flannel. In fact, we are matching and that makes us flannelgays.