O / ob-structĭo
noun

ob-structĭo

gen. ob-structōnis · gender feminine · decl. 3rd
a building before; against, a closing up by building, a blocking up
a building before or against, a closing up by building, a blocking up.
Lit. (post-class.): corporum, Arn. 2, 63.—
an obstruction, a barrier figuratively
Trop., an obstruction, a barrier: haec obstructio non diuturna est, Cic. Sest. 9, 22.