The term 'prickly husk' refers to the protective outer layer of a seed or fruit. The two crossword solutions for this term are 'BUR' and 'BURR, ' both of which refer to the same type of structure. A BUR is a dry, hard, spiny, and often one-seeded fruit that is found on many plants, while a BURR is a similar structure that is composed of hooked bristles or barbs. Both burrs and burs are important for dispersing the seeds of the plant they are attached to.