| Abatis (or Abattis) | Trees cut and arranged to leave the branches facing outwards to form a barrier. |
| Afrancesado | Spaniard loyal to Joseph Bonaparte – literally ‘frenchified one’. |
| Alarmas | Galician Home Guard. |
| Alicantanos | Native of Alicante. |
| Aragónese | Native of Aragón. |
| Bastion | A construction with two front faces protruding into the ditch from the curtain to facilitate flanking fire from both sides along the ditch. |
| Batardeau | A wall built across the ditch of a fortification with a sluice gate to regulate the height of water in the ditch on both sides of the wall. |
| Bomb ship/vessel | A bomb vessel, bomb ship, bomb ketch, or simply bomb was a type of wooden sailing naval ship. Its primary armament was a mortar mounted forward near the bow and elevated to a high angle. |
| Projectiles were shells or carcasses rather than solid shot. |
| Caisson | French artillery ammunition wagon. |
| Carronade | Short, large calibre ship’s gun that looks and operates similar to a howitzer. |
| Casemate | A vaulted chamber for artillery guns. |
| Caçadores | Portuguese light infantry (n.b. Cazadores in Spanish). |
| Chevaux de frise | Portable barrier embellished with swords and spikes. |
| Cortes | Spanish parliament. |
| Counterscarp | The outer wall of the ditch. |
| Cunette | A narrow trench dug in the bottom of a defensive ditch and flooded where possible. |
| Demi-Lune | A triangular outwork built to protect the curtain wall and to provide cover to the flanks of a bastion (see also Ravelin). |
| Embrasure | The gap in the parapet through which the gun was fired. |
| Enfilade | Sweeping fire from a flank. |
| Enceinte | The main perimeter of the fortified location. |
| En potence | The creation of defensive lines connected by a right or obtuse angle. |
| Fascine | Small, solid cylindrical binding of sticks used to rivet trenches and military works. |
| Faussebraie | An earth rampart built to protect the base of the curtain wall. |
| Fernandinos | Supporters of Ferdinand VII. |
| Fléche | Fieldwork made of earth in a “v” shape, with the salient angle facing out from the defence (also known as a redan). |
| Gabion | Large, cylindrical wicker basket filled with stones and earth. |
| Gallego | Native of Galicia. |
| Glacis | Sloping ground immediately in front of the ditch. |
| Guidon | A small flag or pennant carried on a staff, normally by cavalry units. |
| Halberd | Combined spear and battle-axe. |
| Halberdier | Man armed with a halberd. |
| Juramentado | A Spaniard in the sworn service of Joseph Bonaparte. |
| Loophole | Narrow vertical slit in a wall for shooting or looking through. |
| Lugger | Small tug or transport craft. |
| Madrileño | Native of Madrid. |
| Miqueletes | Regular Catalan soldiers but not part of the Spanish Royal units, following a regional tradition from the Spanish wars of succession. |
| Ordenança | Portuguese Home Guard. |
| Ordre mixte | Formation in which column is mixed with line to combine momentum with firepower. |
| Palisade | Strong wooden stake, about three metres long, driven into the ground short of the parapet of the glacis. |
| Parallel | Deep trenches, parallel to the target, which provide cover from fire to the besiegers as they prepared battery positions. |
| Parapet | Wall or bank in front of the trench or rampart that afforded protection to those behind it. Made of earth, masonry or wood. |
| Ravelin | A triangular outwork built to protect the curtain wall and to provide cover to the flanks of a bastion (see also Demi-Lune). |
| Reales | A unit of currency in Spain. |
| Revêtment | A strong exterior restraining wall supporting the front of the rampart and extending down to the ditch. |
| Sap | Trenches that come forward of a parallel in order to construct batteries or new/additional parallels. |
| Serviles | Opponents of the 1812 constitution. |
| Somatenes | Catalan Home Guard: so called because they reputedly turned out when the alarm bell (somanten) was rung. |
| Tarifeños | Native of Tarifa. |
| Terreplein/Terre-Pleine | Surface of the rampart behind the parapet, where guns are mounted. |
| Tête-de-pont | Bridgehead. |
| Tirailleurs | French term for skirmishing troops who were positioned in front of the main body of forces. |
| Toise | A measurement of distance just over six feet or nearly two metres. |
| Trincadours | Small, fast gunboats, capable of being propelled by oar or sail. |
| Trunnion | A trunnion (from Old French “trognon”, trunk) is a cylindrical protrusion used as a mounting and/or pivoting point at the side of the barrel which rests on the carriage. |
| Valencianos | Native of Valencia. |
| Vedette | Mounted sentry placed in advance of an outpost. |
| Voltigeur | French light skirmishers from the 2nd elite company in the battalion. |
| Zaragozanos | Native of Saragossa (ie Zaragoza). |