FMN Share definition Flag Fuck my neighbors (FMN) is used to commonly express your anger towards neighbors. My neighbor's dog shit in my yard, FMN!So what, my neighbors got a new Mercedes, FMN! FMN by Shit my neighbors do September 5, 2011 Words you can keep railfan mug chonk mug chud mug based mug 67 mug slime mug mogging mug chopped mug thot mug glazing mug huzz mug yams mug larp mug unc mug cracked mug simp mug baddie mug bop mug lolcow mug