Definition of as merry as a grig in English:

as merry as a grig

phrase

(also as lively as a grig)
dialect
  • Full of fun; very lively.

    ‘Everyone said Annabelle had been merry as a grig before the man she loved married elsewhere.’
    • ‘I think it was a cricket, but when I heard it, I was merry as a grig!’
    • ‘They were more than fairly high, merry as grigs, and prepared to go on all night.’
    cheerful, happy, cheery, good-humoured, jovial, merry, sunny, bright, joyful, light-hearted, in high spirits, in good spirits, sparkling, bubbly, exuberant, effervescent, ebullient, breezy, airy, lively, vivacious, full of life, sprightly, jaunty