Not sure what it's used for.

It's a pitcher - probably used for claret.  Of course, it helps if you set it upright before filling it with anything :-) 

i had one of these,not to long ago,i bought for i believe $12.00,i resold it for $25.00,not exactly sure what it's true worth is but the person who bought it had no prooblem paying the $25.00 for it.

here is a comparable piece on eBay now item number 112060233281