Definition of downfold in English:

downfold

noun

Geology
  • A syncline.

    ‘His concept of a great downfold or depression filling with sediment at the edge of a continent and then isostatically uplifted to produce the Appalachian fold ranges, was the first suggestion of an Appalachian geosyncline.’
    ‘Beyond the almost level floor of this downfold, the chalk strata rise once more in a line of very sharp flexure, running west and east through South Dorset into the Isle of Purbeck, and through the Isle of Wight.’

Pronunciation

downfold

/ˈdaʊnfəʊld/