perpendicular: a Gothic style in 14th and 15th century England; characterized by vertical lines and a four-centered (Tudor) arch and fan vaulting
gothic: a style of architecture developed in northern France that spread throughout Europe between the 12th and 16th centuries; characterized by slender vertical piers and counterbalancing buttresses and by vaulting and pointed arches
jamming: deliberate radiation or reflection of electromagnetic energy for the purpose of disrupting enemy use of electronic devices or systems