■ adjective
1》 [often in combination ] likely or liable to suffer from, do, or experience (something unfortunate): accident-~ | farmed fish are ~ to disease.
2》 lying flat, especially face downwards.
↘with the palm of the hand facing downwards.
3》 archaic with a downward slope or direction.
Derivatives
~ness noun
Origin
ME: from L. pronus 'leaning forward', from pro 'forwards'.