Green.  Young, inexperienced, unacquainted; ignorant.  How
  green the cull was not to stag how the old file planted the
  books.  How ignorant the booby was not to perceive
  how the old sharper placed the cards in such a manner
  as to insure the game.

Green bag.  An attorney:  those gentlemen carry their
  clients’ deeds in a green bag; and, it is said, when they
  have no deeds to carry, frequently fill them with an old
  pair of breeches, or any other trumpery, to give themselves
  the appearance of business.

Green gown.  To give a girl a green gown; to tumble her
  on the grass.

Green sickness.  The disease of maids occasioned by celibacy.

Greenhead.  An inexperienced young man.

Greenhorn.  A novice on the town, an undebauched young
  fellow, just initiated into the society of bucks and bloods.

Greenwich barbers.  Retailers of sand from the pits at
  and about Greenwich, in Kent:  perhaps they are styled
  barbers, from their constant shaving the sandbanks.

Greenwich goose.  A pensioner of Greenwich Hospital.

Gregorian tree.  The gallows:  so named from Gregory
  Brandon, a famous finisher of the law; to whom Sir William
  Segar, garter king of arms (being imposed on by
  Brooke, a herald), granted a coat of arms.

Grey beard.  Earthen jugs formerly used in public house
  for drawing ale:  they had the figure of a man with a large
  beard stamped on them; whence probably they took
  the name:  see Ben JONSON’S plays, Bartholomew fair,
  &c. &c.  Dutch earthen jugs, used for smuggling gin on
  the coasts of Essex and Suffolk, are at this time called
  grey beards.

Grey mare.  The grey mare is the better horse; said of
  a woman who governs her husband.

Grey parson.  A farmer who rents the tithes of the rector
  or vicar.

Grig.  A farthing.  A merry grig; a fellow as merry as a
  grig:  an allusion to the apparent liveliness of a grig, or
  young eel.

Grim.  Old Mr. Grim; death.

Grimalkin.  A cat:  mawkin signifies a hare in Scotland.

Grin.  To grin in a glass case; to be anatomized for murder: 
  the skeletons of many criminals are preserved in glass
  cases, at Surgeons’ hall.

GRINAGOG, the cat’s uncle.  A foolish grinning fellow,
  one who grins without reason.

Grinders.  Teeth.  Gooseberry grinder; the breech.  Ask
  bogey, the gooseberry grinder; ask mine a-se.

To grind.  To have carnal knowledge of a woman.

Groats.  To save his groats; to come off handsomely:  at
  the universities, nine groats are deposited in the hands of an
  academic officer, by every person standing for a degree;
  which if the depositor obtains with honour, the groats are
  returned to him.