does the singular form of this noun ends with the letter "y"?
No, the singular form ends with F. However, my word (the plural form) does not have an F in it. [:O]
Is it edible? Some are.
Can we find it in the market? Some can be found in a food store or market.
Can you give clues about the color? size? shape? There are various colors, but a typical color is green. However, the color also tends to change as these things become older and/or after they leave their original location. The sizes and shapes are also varied, but I can tell you that they are normally quite thin, and you could fit lots and lots of them into a shopping bag.