'Heads' in the Bible

And Ruth the Moabitess said to Naomi, Now let me go into the field and take up the heads of grain after him in whose eyes I may have grace. And she said to her, Go, my daughter.

And she went, and came and took up the heads of grain in the field after the cutters; and by chance she went into that part of the field which was the property of Boaz, who was of the family of Elimelech.

And let some heads of grain be pulled out of what has been corded up, and dropped for her to take, and let no sharp word be said to her.

So she went on getting together the heads of grain till evening; and after crushing out the seed it came to about an ephah of grain.