I was very surprised when I said that hashing the same data twice was "double pass" and a comment came in that this wasn't the case if the hashing could be performed in parallel. This would mean that calling CCM/EAX a "two pass" system or GCM a 1.5 pass system would be wrong.
I've always understood that if data is "passed through", a primitive (possibly using some mode of operation in case of a block cipher) that this counts as a "pass". Here, "passed through" would mean that the data is transformed or taken into account for a calculation (generally through an "update" function for an implementation of an algorithm).
However, there might be a difference in having to go back to the start of the algorithm, e.g. for AES-SIV, or if the operations such as MAC-then-encrypt can be performed in parallel. In the latter case I could imagine somebody arguing that you would "pass over" the data once where "pass" is read more as "traversing" over it while taking it into account.
Is there a clear definition of something being a "pass" or a common understanding of the term? If it means "pass over" do we have another term for requiring the data through two cryptographic primitives?