Lewis & Short

sēmĭ-rŭtus, a, um, adj. [ruo], halfpulled down, half-overthrown, half-demolished, half-destroyed, half-ruined (not anteAug.; freq. in the historians, esp. in Liv.): murus, Liv. 31, 26; 32, 17: tecta, id. 10, 4; Luc. 1, 24: vallum, Tac. A. 1, 61: castella, Liv. 28, 44; Tac. A. 4, 25: urbs, Liv. 5, 49; 31, 24: plus negotii fuit cum semirutā Karthagine quam cum integrā, Flor. 2, 15, 13: patria, Liv. 26, 32 et saep.: telae confuso stamine, half-torn, Claud. Rapt. Pros. 3, 155.
Neutr. plur. as subst.: sēmĭrŭta, ōrum, n.: partim per semiruta partim scalis integros muros transcendere, the halfdemolished parts of the wall, Liv. 36, 24, 6 (dub.; Weissenb. semirutos): semiruta moenium, App. Flor. 2, p. 350, 30.