mater is Latin, not English.

Hi WA

mater = BrE (old-fashioned) mother
pater = BrE (old-fashioned) father

It's still Latin. I suspect that people who try to use it in everyday conversation today will look like incredible snobs. Like saying "I'm from the social class that sends their children to really good schools."

Hi Barbara

I think 'paternal' and 'maternal' are fine but, as you say, 'mater' and 'pater' are to be avoided.

They can be used facetiously. I wouldn't dismiss them as just being snobbishness.

Hi,

Americans sometimes talk about their Alma Mater (Latin again).

Clive

The dictionaries say that mater is used in BrE.

'Paternal' and 'maternal' are fine when used as follows:

paternal grandmother, maternal grandmother

Neeraj JainThe dictionaries say that mater is used in BrE.

Hi Jian

I think your dictionaries belong to the old editions.

mater

ma·ter (plural ma·ters

For some reason, this thread reminds me of an old, humorous song:

Hello Muddah, Hello Fadduh
Here I am at Camp Granada
Camp is very entertaining
And they say we'll have some fun if it stops raining.

[8]