n. The act of fortifying or strengthening.n. The art or science of strengthening military positions in such a way that they may be defended by a body of men much inferior in number to those by whom they are attacked.n. That which fortifies, strengthens, or protects.n. Specifically A military work, consisting of a wall, ditch, palisades, etc., constructed for the purpose of strengthening a position; a fortified place; a fort; a castle.n. the polygonal or caponiere systemn. the tenailled system, andn. the bastioned system. To these in modern times may be added the armored or turreted system. Mahan. Synonyms Fortification, Bulwark, Castle, Citadel, Fort, Fortress, Mamelon, Rampart, Redan, Redoubt. Fortification is the only one of these words that is used for the art or science, or for all classes of defensive works; the others represent kinds of fortification. Thus, fortress represents a large, and fort, generally, but not always, a smaller stronghold, defensible on all sides, as Fortress Monroe, Fort Sumter. See the definitions of the words.