מְצוּרָה mᵉtsûwrâh (H4694)

a hemming in, i.e. (objectively) a mound (of siege), or (subjectively) a rampart (of protection), (abstractly) fortification

1) siege-works, stronghold, rampart 1a) siege-works 1b) rampart

or מְצֻרָה; feminine of מָצוֹר (H4692);