While there is some overlap, I believe a distinction can be made.
Question: Does at least one deity exist?
Agnostic: (shrugging) Maybe....
Weak atheist: I see no reason to think so, although I can't definitively rule it out.
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Question: Does at least one deity exist?
Agnostic: (shrugging) Maybe, .......maybe not.
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My addition is the phrase “maybe not.”
I am probably splitting hairs but this is the typical response from an agnostic. They are noncommittal because they claim that they cannot know.