opa

noun

1. Grandfather, grandpa.

   “We love to eat: Opa's apple cake […] My opa (grandfather) had a long and beautifully kept allotment in the north German town of Flensburg.”

   “I intuited that somehow I’d always been, yet, clearly, there was time — a considerable time — when I was not. So, where was I? I didn’t have an opa to ask.”

   “That story of him playing football on his crutches I’ve heard from at least four people: my grandparents, my mum and one of the other boys, who’s since become a mildly creepy evangelical Christian. He retold it to me at my opa’s funeral, about half a century after the game. It’s true that I asked my opa some less than tactful questions on that visit. […] My opa had actually started writing a memoir once before, soon after my oma died.”

   “My children have an oma and an OPA, so I knew that I could put in the O and the A.”

   “My opa grew up poor in Vienna and then got a scholarship to a prestigious Jewish high school.”

2. (abbreviation, alt-of, countable)Abbreviation of optionally piloted aircraft.
3. (abbreviation, alt-of, initialism, uncountable)Initialism of offensive patent aggregation.