noun, technical - a long beam or structure that is fixed at one end and free at the other
noun - a glass container in which plants or small animals are kept and grown in controlled conditions
noun - a person who sees a crime or an accident happen and can describe what they saw
adjective - describing petrol that does not contain lead, which is less harmful to the environment and engines
verb - to decide which tasks, problems, or goals are the most important and deal with them first