droop

Concise Oxford English Dictionary © 2008 Oxford University Press:
droop/druːp/

▶verb bend or hang downwards limply.

■ sag down from weariness or dejection.

▶noun an act or instance of drooping.

– derivatives
droopily adverb,
droopiness noun,
droopy adjective (droopier, droopiest).

– origin ME: from ON drúpa ‘hang the head’; rel. to drip and drop.