How do you spell Shard

Available Definitions:
1)  n. - A plant; chard.
2)  n. - A piece or fragment of an earthen vessel, or a like brittle substance, as the shell of an egg or snail.
3)  n. - The hard wing case of a beetle.
4)  n. - A gap in a fence.
5)  n. - A boundary; a division.