A male hawk, esp. the male peregrine.
Origin of tiercel
- From Middle French terÃ§uel, from Late Latin tertiolus, the diminutive of Latin tertius (“third"). Sources disagree whether the connection is that the males of most species of birds of prey favoured in falconry are smaller than the females by about a third, or whether it refers to the supposition that only one egg in three yields a male.