What is the meaning of Groat?

Hulled grain, chiefly hulled oats.

Any of various old coins of England and Scotland.

2. Any unit of currency worth four pence.
4. A historical English coin representing such a unit: a silver coin worth four English pennies, still minted as one of the set of Maundy coins.

   Any unit of currency worth four pence.

   A historical English coin representing such a unit: a silver coin worth four English pennies, still minted as one of the set of Maundy coins.

   A proverbial small sum; a whit or jot.

   Source: wiktionary.org