What term describes a method of antenna impedance matching that uses a short section of transmission line connected to the antenna transmission line near the antenna and perpendicular to the transmission line?

A stub match consists of a short section of transmission line (a "stub") connected in parallel to the main feedline. This stub is usually attached perpendicularly near the antenna to cancel out reactive components and match the antenna's impedance to the feedline. Distractors like the gamma, delta, and omega matches are entirely different methods. They involve attaching rods, wires, or capacitors directly to the physical driven element of the antenna itself, rather than splicing an extra piece of transmission line into the main feedline.