As in all questions of interpretation, this is a judgment call, and even more judgment is required in this case, because Godot never arrives and his absence is never explained. What's more, since this play is considered theater of the absurd, we must carry with us the possibility that the search for meaning will be frustrated (that we'll always wait for meaning as the tramps wait for Godot).
We must therefore deduce what meaning we can from the information given. The tramps are promised that Godot will arrive; he never does. It seems important that he arrive; he never does. They keep waiting, and weirdness occurs while they do. One of the most common interpretations of Godot is that he is meant to stand in for any final, transcendent answer. Think of the Marxist utopian state; it never really arrives. Think of Heaven; we don't get there and it doesn't arrive. Nor does Jesus, or any final answer. In this model we wait for Godot because that's what our philosophies do: they seek a final summation.
Godot's name also suggests such possibilities. "God" and "ot" which can be read as "aught" (nothing) or "o" (also nothing), or as "God /dot" (in which the entirety of God retreats via perspective to a tiny dot in the distance).