In gaming terms creating a character with ridiculous stats, abilities, kit, perks etc. Usually with the express purpose of breaking game balance and/or reducing the GM to a gibbering wreak.
Min/Maxing can be said to be crude stat based flangineering often employed by munchkins.
GM: Yeah he took the gift Blade of Heimdall just so he could stab a Black Spiral to death with a silver toothpick....f**king flangineering bastard!!