Don't worry stan, you are slightly above average if you think the definition of small depends on the comparision between you and others.
Also in that same vein if you caompare yourself to the others on this site then you are small, and so am I.
For me personally I view small medium and large in terms of they applicability to being used. I think a penis that does not give enough pleasure is small, one that gives an ordinary amount of pleasure is medium, one that gives the most amount of pleasure is big, and one that gives more pain than pleasure is huge. In this categorization rainbow I do not know where I fit because I have not fucked myself, therefore I know not what it can do; I have only heard testimony, and it has for the most part been positive.
So in closing(lol) ask your partners if you're small... not us.
we're not the experts.