noun

• (philosophy) An abstract archetype of a given thing, compared to which real-life examples are seen as imperfect approximations; pure essence, as opposed to actual examples.
• (obsolete) The conception of someone or something as representing a perfect example; an ideal.
• (obsolete) The form or shape of something; a quintessential aspect or characteristic.
• An image of an object that is formed in the mind or recalled by the memory.
• More generally, any result of mental activity; a thought, a notion; a way of thinking.
• A conception in the mind of something to be done; a plan for doing something, an intention.
• A purposeful aim or goal; intent
• A vague or fanciful notion; a feeling or hunch; an impression.
• (music) A musical theme or melodic subject.