tectum
noun
tec·tum ˈtek-təm 
plural tecta ˈtek-tə
: a bodily structure resembling or serving as a roof
especially : the dorsal part of the midbrain
tectal
ˈtek-tᵊl
adjective 
Example Sentences
Recent Examples on the Web And in the tectum, a brain region that processes images from the optic nerve, the neurons of salamanders were often strewn chaotically about—a trait seen in embryonic or larval brains—whereas in frogs, the neurons were nicely layered. 
Douglas Fox, Scientific American, 1 Feb. 2022 The researchers also recorded activity from the ocular tectum, a brain area involved in basic visual processing in owls and many other vertebrates. Joanna Klein, New York Times, 3 July 2018
Douglas Fox, Scientific American, 1 Feb. 2022 The researchers also recorded activity from the ocular tectum, a brain area involved in basic visual processing in owls and many other vertebrates. Joanna Klein, New York Times, 3 July 2018 Word History
Etymology
New Latin, from Latin, roof, dwelling, from neuter of tectus, past participle of tegere to cover — more at thatch
First Known Use
circa 1905, in the meaning defined above
Medical Definition
tectum
noun
tec·tum ˈtek-təm
plural tecta -tə
1
: a bodily structure resembling or serving as a roof
2
: the dorsal part of the midbrain including the corpora quadrigemina
called also tectum mesencephali