There are 4 calories in 1 ounce of Iceberg Lettuce (Includes Crisphead Types). Calorie breakdown: 8% fat, 76% carbs, 16% protein.
Cryptosporidium (crip-toe-spor-ID-ee-um) is a protozoan, a single-celled parasite that lives in the intestines of animals and people.
Words don't have to be used often to be words. For instance, cryptosporidium is a word which is used less often by the people you meet than funner. Yet, the anchorwoman of your six o'clock news show would probably use cryptosporidium when appropriate, while avoiding funner in favor of more fun.