The phrase "a definite position" is correct and can be used in written English.
You can use it to refer to a settled or established attitude or opinion. For example, "The board was adamant to take a definite position on the issue."
We have a definite position on dealing with Putin, whose ambitions are increasingly unnerving.
Each of these points has a definite position on the x and y axes of the work plan.
After all, the moon is made of these particles, and quantum theory holds that until it is observed, a particle doesn't have a definite position.
If you measure the position of Jupiter then you are measuring something real: Jupiter has a definite position and you can estimate the probable error in your observations.
Mr. Romney has not taken a definite position on it, though he has said he sees no reason to change it.
It tends to suggest incorrectly that the electron really has a definite position and velocity and that they simply have not been determined.
And one of the most significant Founders of this country, Benjamin Franklin, was, by common acknowledgment, a "Deist," not taking any definite position on the issue of religion in his many writings.
To predict the position of the planet at any time it is necessary to know the time when it passed through any definite position; e.g., its time of perihelion passage.
"The Church has a very definite position: when weapons serve to protect the Fatherland, the Church supports both its creators and the soldiers who use it," Mr Volkov was quoted as saying.
"He said he had never dissociated himself and never will and that was a much more definite position that he had ever adopted before".
