Which term refers to a short pillar or column used for support?

The term that refers to a short pillar or column used for support is "baluster." Balusters are typically found in railings and as structural supports in various types of architecture, particularly in staircases and balconies. They are designed not only for stability but also to serve a decorative function, contributing to the overall aesthetic of a space.

The other terms have distinct meanings and applications in the art and architectural context. An amphora is a type of container used in ancient times for storing liquids like oil or wine, often with two handles and a long neck. A tondo is a circular painting or relief, often used in the context of fine art, and does not imply any sort of structural support. Crenellation refers to the notched parapets found in fortifications, allowing for defensive positions, and is unrelated to the concept of a supportive column.