Faith is a measure of irrationality

[Esquilax]

May I call that faith? Can faith be defined as “believing what is likely, but not confirmed” or am I taking too much liberty?

One thing worth noting is that, in this case, nobody is believing anything, we're just not excluding the possibility based on the evidence at hand. I suppose in some way we're believing in the possibility, but that's not saying very much, and if that is faith, it's not exactly comparable to religious faith.