Nouns

(n)capa tight-fitting headdress
(n)capa top (as for a bottle)
(n)detonator, detonating device, capa mechanical or electrical explosive device or a small amount of explosive; can be used to initiate the reaction of a disrupting explosive
(n)capsomething serving as a cover or protection
(n)cap, pileusa fruiting structure resembling an umbrella or a cone that forms the top of a stalked fleshy fungus such as a mushroom
(n)hood, capa protective covering that is part of a plant
(n)ceiling, roof, capan upper limit on what is allowed“he put a ceiling on the number of women who worked for him”, “there was a roof on salaries”, “they established a cap for prices”
(n)crown, crownwork, jacket, jacket crown, cap(dentistry) dental appliance consisting of an artificial crown for a broken or decayed tooth“tomorrow my dentist will fit me for a crown”
(n)capital, chapiter, capthe upper part of a column that supports the entablature

Verbs

(v)cap, crestlie at the top of“Snow capped the mountains”
(v)caprestrict the number or amount of“We had to cap the number of people we can accept into our club”