tiercel
noun
tier·cel ˈtir-səl 
variants or tercel
ˈtər-səl
: a male hawk
especially : a male peregrine falcon
Word History
Etymology
Middle English tercel, from Anglo-French, from Vulgar Latin *tertiolus, from diminutive of Latin tertius third; probably from the fact that the male is about one third smaller than the female
First Known Use
14th century, in the meaning defined above