[noun] [U] - grass which is cut, dried and used as animal food or as covering materialIf you make hay while the sun shines you make good use of an opportunity.Hay fever is an illness caused by pollen which gives you watery, itchy eyes and makes you sneeze.Sue suffers from hay fever.
HAY
Meaning of HAY in English
Cambridge English vocab. Кембриджский английский словарь. 2012