One of two varieties of head lettuce (the other being butterhead). It's commonly known as iceberg, which, in truth, is a variety of crisphead. Other varieties include Great Lakes, Imperial, Vanguard and Western. Crisphead lettuce comes in large, round, tightly packed heads of pale green leaves. Though crisp, succulent and wilt-resistant, all crispheads have a rather neutral flavor. Choose those that are heavy for their size with no signs of browning at the edges. See also lettuce.