grundies
/ˈɡrʌndɪz
/plural noun informal, chiefly Australian /NZ
Underpants: he had his trousers and his grundies round his ankles...
- He was pictured proudly holding his baby, not grappling with his grundies.
- Not much fun, though, with my damp grundies beginning a savage chafing.
- The soiled grundies were disposed of in the traditional manner - down a nearby pub toilet.
Origin
1990s: from undies, influenced by the name Reg Grundy (b. 1923), an Australian media producer.