Peaky

He's going to be very weak and peaky for the next couple of days.

Are you all right, mate? It's just you look a bit peaky.

You look a bit peaky.

Her appetite did not improve, however, and she looked very thin and peaky.

Or over hills with peaky tops engrail'd, / And many a tract of palm and rice, / The throne of Indian Cama slowly sail'd / A summer fann'd with spice.

A wide spread of possible outcomes will give a relatively flat distribution and so indicate a risky project. A narrow spread of results will give a very peaky graph and indicate a low risk project.