Cavity and solid walls. 1  A cavity wall is made up of two walls with a gap in between, known as the cavity; the outer leaf is usually made of brick, and the inner layer of brick or concrete block.  A solid wall has no cavity; each wall is a single solid wall, usually made of brick or stone.
A cladogram (from Greek clados branch and gramma character) is a diagram used in cladistics which shows relations among organisms.
Full Definition of PARALLELOGRAM. : a quadrilateral with opposite sides parallel and equal. See parallelogram defined for English-language learners.See parallelogram defined for kids.ull Definition of PARALLELOGRAM. : a quadrilateral with opposite sides parallel and equal. See parallelogram defined for English-language learners. See parallelogram defined for kids.