A corner is the place where two walls meet at an acute angle, and is generally thought to be the least beneficial position to be in a life-or-death situation. From this notion was born the verb to corner, which is used to mean "To back (another person or animal) into a corner" and usually also implies foul play. This article is about structural, boundary and retaining walls. ... This article is about angles in geometry. ... In colloquial English, person is often synonymous with human. ... Phyla Porifera (sponges) Ctenophora (comb jellies) Cnidaria Placozoa Bilateria Acoelomorpha Orthonectida Rhombozoa ?Myxozoa Superphylum Deuterostomia    Chordata (vertebrates, etc. ...