Gry is an obsolete unit of measurement, equal to one tenth of a line, which is in turn one twelfth of an inch. Hence, a gry is 120th of an inch, or 211 and two-thirds of a micrometre, presuming international inches are used.
There is also a riddle as follows:
- "Angry" and "hungry" are two words that end in "gry". There are three words in the English language. What is the third word? Everyone knows what it means and everyone uses it every day. Look closely and I have already given you the third word. What is it?
- The answer is: "language", the third word in "the English language". The words "angry" and "hungry" are just red herrings.
The riddle is so commonly misquoted it has become a source of constant irritation for reference librarians.