The term 'shape of an ingot' refers to the form of a metal BAR that has been cast from molten metal. The crossword solution for this term is BAR, which is a three-letter word. A BAR is a long, thin, and usually rectangular shape, which is the most common form of an ingot. Bars are used in many industries, such as manufacturing, engineering, and construction, and are often used as raw materials for further processing.