caul
Concise Oxford English Dictionary © 2008 Oxford University Press:
caul /kɔːl/
▶noun
- 1 the amniotic membrane enclosing a fetus.
■ part of this membrane occasionally found on a child's head at birth, thought to bring good luck.
- 2 Anatomy the omentum.
– origin ME: perh. from OFr. cale ‘head covering’.
'caul' also found in these Oxford entries:

