Web site: https://www.butlersantiques.com/
This is a decanter type known as a 'mell'. They were popular in the mid-late 19th century and this is typical, although the rich deep blue colour is not very apparent in my image. (I'll try to take a better one!)
A mell typically has a very low squat bulbous body and a long neck which tapers slightly below the widely flanged lip. This is no exception. It has a hollow ball stopper.
It would serve well for white wine or spirits and is very fit for purpose, being without any chips or cracks.
English, c.1880, 11.3", 28.7 cm. high incl. stopper.