(idiomatic) In Australia.
Surfing is a popular sport down under.
(idiomatic) Into Australia; to Australia.
We traveled down under for our vacation.
By extension, anywhere, or to anywhere, south of the Equator
(euphemistic, rare) Hell; in Hell.
Source: en.wiktionary.orgAfter two and a half weeks he began to break down under the strain. Source: Internet
Americans stranded in Peru had to fend for themselves in the unfamiliar, non-English-speaking country locked down under emergency conditions. Source: Internet
As the once-confident vision of a global world broke down under the coronavirus pandemic, the press sought to provide authoritative guidance to the public, clothed in the mantle of what it presumed was science. Source: Internet
Any given material will break down under a strong-enough electric field, and some materials of interest in electrical engineering are "non-ohmic" under weak fields. citation citation Ohm's law has been observed on a wide range of length scales. Source: Internet
Australia is not the first place that comes to mind when thinking of extreme death metal, and Black Lion Records are proud to present one of the darkest secrets kept down under." Source: Internet
Brooke, 2004. p. 127 Petrels obtain food by snatching prey while swimming on the surface, snatching prey from the wing or diving down under the water to pursue prey. Source: Internet