noun the upper part of a retort.
2. helmet ·noun that which resembles a helmet in form, position, ·etc.
3. helmet ·noun a naked shield or protuberance on the top or fore part of the head of a bird.
4. helmet ·noun the hood-formed upper sepal or petal of some flowers, as of the monkshood or the snapdragon.
5. helmet ·noun a defensive covering for the head. ·see casque, headpiece, morion, sallet, and ·illust. of beaver.
6. helmet ·noun the representation of a helmet over shields or coats of arms, denoting gradations of rank by modifications of form.
7. helmet ·noun a helmet-shaped hat, made of cork, felt, metal, or other suitable material, worn as part of the uniform of soldiers, firemen, ·etc., also worn in hot countries as a protection from the heat of the sun.