Old-fashioned term for dating, could mean anything from holding hands to a sweaty shag in a haystack. Generally used by people who still call a radio a wireless.
A girl with a very sexy body but an unattractive face... This phrase is generally uttered by men who examine the posterior of a lady as they drive by, On the approach they say "Oooohhh" and if her face does not match the beauty of her posterior as they pass they will say "Naaaaaa", hence Una.