veritable
Truly real or genuine, not an exaggeration at all.
Veritable means genuine, authentic, or true to such a degree that the description is not an exaggeration. When you call something veritable, you're emphasizing that what you're saying is literally, actually true, even though it might sound like you're exaggerating.
If your basement flooded after a storm and there's water everywhere, you might call it a veritable lake in your basement. The description is accurate: there really is that much water. When a librarian describes a student as a veritable bookworm, she means the student genuinely reads constantly. A teacher might call a particularly challenging math problem a veritable puzzle, meaning it really does require puzzle-solving skills to crack.
The word adds emphasis and conviction to your description. It's like saying “I'm not kidding” or “no exaggeration.” When someone discovers a veritable treasure trove of old comics in their attic, they've found so many valuable comics that calling it a treasure trove is actually accurate, not just colorful language.
Veritable often appears before metaphors to signal that the comparison is more literal than it sounds. A garden might be a veritable jungle if it's truly overgrown and wild, not just a little messy.