The phrase "a definite step" is correct and usable in written English.
It can be used to indicate a clear and specific action or decision taken towards a goal or objective.
Example: "Implementing a new training program is a definite step towards improving employee performance."
Alternatives: "a clear move" or "a specific action".
That said, it's a definite step up from Coach Trip.
It's a definite step away from last year's design.
He's a definite step up from David Jones.
After all, it's a definite step away from the style that previously failed to engage.
A step up academically, Yale was a definite step down on the field.
"I think this represents a definite step ahead," Richard Danzig, secretary of the Navy, said in an interview.
They're expensive, but considering the chaos of the typical airport terminal, especially when flights are delayed or cancelled, well worth it--a definite step up from sitting on the floor next to the gate, fighting over the last available power outlet.
NERD DISCLAIMER: To conclude, Black Ops is a much improved Call of Duty experience, a definite step-up from Modern Warfare 2 which many saw as lazy and short.
After the terrific Resi 4, Resident Evil 5 felt like a very definite step in the wrong direction, an accomplished action title but generic with it, and the three-part Resident Evil 6 suffered for two-thirds of its campaign being, well, kind of boring, basically.
1937 London Urges Armistice LONDON — The British government has taken the first definite step to bring about a cessation of hostilities in Spain by proposing an armistice during which the foreign volunteers fighting on both sides might be withdrawn.
With country put on the back burner, and soul and R&B left in Memphis, what was left was very classy, very clean white pop perfect for the Las Vegas crowd, but a definite retrograde step for Elvis".
