" one hand ass" is a term used to gauge the size of a women's ass that is ripe for fucking. to create your own gauge take your right hand then make a fist then spread your thumb and little finger as far apart as possible. What ever women's ass width falls close to the gauge is worth being sexy with. The women are then known as "one handers"
How to use in conversation
1) Russ " I fucked this women last night" , Phil " was she a one-hander ?" , Russ " No, I knew I shouldn't of fucked her fat ass"
2) Russ " look at her ass she's got a one-hander", Phil " Fuck me your right, lets stalk her"
3) Phil " I've got a new girlfriend with a one hand ass", Russ " expose yourself, force your intentions upon her and impregnate her "