<p><strong>Noun</strong></p><ul><li>any conception existing in the mind as a result of mental understanding, awareness, or activity.</li><li>a thought, conception, or notion: That is an excellent idea.</li><li>an impression: He gave me a general idea of how he plans to run the department.</li><li>an opinion, view, or belief: His ideas on raising children are certainly strange.</li><li>Synonyms: judgment, sentiment</li><li>a plan of action; an intention: the idea of becoming an engineer.</li><li>a groundless supposition; fantasy.</li><li>Philosophy: a concept developed by the mind.</li><li>a conception of what is desirable or ought to be; ideal.</li><li>(initial capital letter) Platonism: Also called form.</li><li>an archetype or pattern of which the individual objects in any natural class are imperfect copies and from which they derive their being.</li><li>Kantianism: idea of pure reason.</li><li>Music: a theme, phrase, or figure.</li><li>Obsolete: a likeness, a mental image.</li></ul>