From Longman Dictionary of Contemporary Englishdreamerdream‧er /ˈdriːmə $ -ər/ noun [countable]1REAL/NOT IMAGINARYsomeone who has ideas or plans that are not practical
She was a dreamer – not pragmatic.2DREAMsomeone who dreams while they are asleepExamples from the Corpusdreamer• Douglas C.. Engelbart was constitutionally a dreamer.• Their second daughter is a dreamer and a tomboy.• Not a dreamer at all, but a man waiting for history to catch up with him.• Bedwyr, the poet and dreamer, who suffered ten times over for one grief, was the finer man.• Children are dreamers - they want to be doctors, ballerinas, nurses, and more.• There are those who wish to reconcile everybody concerned; but they are dreamers.• He started to sing: Beautifuldreamer, wake unto me; starlight and dewdrops are waiting for thee.• Visions of dreamers were too frequently interred with their spirits.