There are many applications of "pairwise", for instance different, disjunct, orthogonal, independent, intersecting, connected, and many more. Some of them like "pairwise intersecting" or "pairwise connected" seem meaningful. But most of them appear to express no more information than with "pairwise" deleted. Who introduced this expression in mathematics in what framework?
[Math] Who invented the expression “pairwise different” and what is its advantage over “different”
ho.history-overviewterminology
Best Answer
However "distinct" may have the weaker meaning of not all coinciding. So, in case I would therefore use pairwise, for clarity (see e.g. here), like in the other situations you listed.
The fact is that, in lack of a standard agreement on a definition or a notation, people is led to use more specific forms than needed. For instance: some people use $\subset$ for inculsion, some for strict inclusion. Result: some use $\subseteq $ for weak and $\subsetneq $ for strict inclusion, to avoid any doubt. (Or, I once heard somebody -maybe myself, using the expression, for a topology which is (comprable and) not stronger than another, weakly weaker ).