The phrase "a realistic idea" is correct and usable in written English.
It can be used when discussing concepts, plans, or suggestions that are practical and achievable.
Example: "After reviewing the project requirements, I believe we have come up with a realistic idea that can be implemented within our budget."
Alternatives: "a practical notion" or "a feasible concept."
However, he said that was "not a realistic" idea.
"Saul had a romantic idea, meaning not a realistic idea," his biographer, Sanford Horwitt, told me.
You may not have a realistic idea of the figures involved".
"It's like if you averaged out the weather for all of Australia, it wouldn't necessarily give you a realistic idea of what's going on in Melbourne or Sydney".
Is the routine we see at the beginning a realistic idea of what you might see at a Broadway audition today?
"They have to do their own statistical sampling of their portfolios to get a realistic idea of what those numbers are," Ms. Tavakoli said in an interview.
There is no acceptable test in major league baseball for human growth hormone, hence no one has any realistic idea of who is using performance-enhancing drugs.
"Inter-faith dialogue" may sound a wishy-washy concept; but it is a more realistic idea than presenting a secular peace to competing faiths without the backing of religious leaders.
Thanks to a soaring dollar and a collapsing euro, retirement in Europe is a more affordable and therefore a more realistic idea than it's been in nearly two decades.
An excerpt from Paddington gave what was probably a very realistic idea of the film: a wacky live-action comedy about the well-known young ursine hero from Peru who floods the bathroom and sends the tub whooshing down the stairs in a deluge of water.
In "The Essence of Truth," meanwhile, Heidegger proposed a different and, to my mind, a more realistic idea of truth than any I'd encountered before.
