Just arguing semantics here. People always talk about various things being similar to a circumcision, or even think of them as 'a kind of circumcision'.
One could wear his foreskin retracted 24/7 which would have most of the same health benefits as being circumcised. Or one could be born without a foreskin (aposthia).
Even though the former is often referred to as autocircumsion and the latter is often described as 'born circumcised' these are not the same thing as having been circumcised.
Circumcision is the act of having one's foreskin cut off, it literally means 'cut around'.
Thus in order to be circumcised one had to have a foreskin at one point which was then cut off.
Obviously if one still has his foreskin and simply wears it retracted then really nothing was cut off and the original state can be restored at any time by pulling the foreskin forward. So while it may share certain characteristics with being circumcised, it is not the same thing.
Likewise if one never had a foreskin it wasn't cut off, so a person born without a foreskin has technically not been circumcised.
In many cultures enduring the act of having ones foreskin removed had the greater (very often spiritual or religious) significance -- some belief systems regard the pain and/or bleeding as an essential requirements. Not having a foreskin afterwards was simply one of the benefits as well as an instant proof that the cut has taken place.
- I have never heard how various African cultures with a circumcision tradition handle it if someone is born without a foreskin. I would not be surprised if they still required some sort of cut. Being recut in the traditional manner (without anesthetics) certainly appears to be an option in some cultures if one had a hospital circumcision earlier.
- Judaism has very strict requirements how a circumcision is to be performed and it has to be done as part of a religious ritual called the bris. If one has no foreskin (because of a previous medical circumcision or because one is born without one) there is a separate ritual (called hatafat-dam) which includes drawing a drop of blood so as to 'validate' the circumcision under religious rules.
- In Islam circumcision is technically not a religious rite, it is only mandated for hygiene so anyone who does not have a foreskin would be considered circumcised. This matters particularly in some East Asian countries where sometimes children are born with such a short foreskin that they are regarded as born circumcised (i.e. they are considered to be circumcised even without going through the cut).
