Cervical lordosis is a curve in the cervical spine, the area of the spine which contains the neck vertebrae. This curve is entirely normal and in fact desirable because it helps to stabilize the head and spine, but when the curve straightens out, becomes too deep, or faces in the wrong direction, it can become a problem.
If something's canonical, it follows a principle or rule, usually in a religious or church-related situation. It is also used in mathematics, music and can refer to something reduced to its most basic form.
Definition of canonical for English Language Learners. : 1  connected with or allowed by the laws of the Christian church. : 2  of or relating to the books that are considered to be part of a religion's official text. : 3  of or relating to the group of books, plays, poems, etc., that are traditionally considered to be very important.