noun
provender, fodder, roughage, forage, feed; see also grass 1.
Types of hay include: red clover, wild hay, timothy, sweetgrass, alsike, sweet clover, soybeans, swamp hay, alfalfa, oat hay, millet.
hit the hay*
make hay out of
profit by, utilize, turn to one's advantage; see use 1.
make hay while the sun shines
opportunize, take advantage, make the most of an opportunity; see use 1.