It is correct, but not very common, to use breakfast (desayunar), lunch (almorzar), snack (merendar) and dine (cenar) as verbs.
For example:
She breakfasts on her own every morning.
I am lunching with two friends.
They always snack on crisps.
He is dining with his wife.
In general, we use the expression have + breakfast/lunch/a snack/dinner.
For example:
She has breakfast at 7:00am every morning.
We are having lunch with our colleagues today.
My kids are having a snack right now.
Tonight, we are dining with our parents.