The gill is a unit of volume in the imperial unit system and uses the symbol gi.
It represents 1/4 of a pint - so in this instance, it is 1/4 of an imperial pint - therefore measures exactly 142.0653125 ml. It's also equal to 2 imperial cups and 1/32 of an imperial gallon.
It is pronounced with a "J" sound at the beginning - and it actually part of a humorous in the nursery rhyme 'Jack & Jill'.
In the UK it was used throughout pubs as standard measures; for example spirits were served as 1/6 gill as standard. In Scotland it was 1/5 gill and in Ireland 1/4 gill. It's still used in the Republic of Ireland today.
The US dry pint is a unit of volume in the US customary system with the symbol dry pt.
1 US dry pint is equal to 1/8 of a dry gallon. This is equal to 1/2 US dry quart or 33.6003125 in³.
The dry pint was derived from the the British corn gallon which was 1/8 the standard 'Winchester' bushel or corn. This was the equivalent of 268.8 in³ when in dry form.