My grandmother was "Gerwoman". :)
- O avô = grandfather, with a hat
- A avó = grandmother, with a feather
- Os avós = grandparents, in a departure from many of the PT words covering both genders this one takes the feminine word but becomes masculine (as usual).
Meanwhile, "avo" without the accents somehow is related to fractions as in, 5/12 = cinco doze avos.
But I cannot find much online about this. Well, here you go: