I would if I were talking to a Bayesian, interpret it as meaning something where a "B is evidence for A" if rough calculation shows that P(A|B) > P(A). I don't generally expect rationalists to even mention individual data points unless P(A|B)/P(A) is large, but if someone else gave the data as an example, then I wouldn't expect it to be necessarily large if a Bayesian referred to as evidence. So for example, I could see a Bayesian asserting that the writing of the Bible is evidence for a global flood some 5000 years ago, but I'd be deeply surprised if a Bayesian brought this up in almost any context because the evidence is so weak (in this case P(A|B)>P(A) but P(A|B)/P(A) is very close to 1).