look up any word, like tribbing:
The area on one's foot covered by the strap of their flip/flop. Your mervis can expand and detract depending on the size of your flip/flop strap.
I've been wearing sandals all year long and I have extreme callouses on my mervis.

My mervis hurts real BAD! (say it like Napolean Dynamite)
by Maffs and Sarsar July 22, 2005
a person who likes to be fat and dumb
omg... shes such a mervi AND SHES FAT
by wowman March 27, 2012