Best definition
Used by officious officials at animal shows (eg Crufts) as a request for an animals poncy aristocratic name

official: Fido, whstshowname?

owner: Rumptious Strawberries-Gidlefunk the Third
Whatshowname: define #2
Pronounced similarly to, “What’s your name?” its meaning is the same as”How you doin’?” and other similar “pick-up” lines
“Hey baby, whatshowname?”