What does "between positions" probably mean?

[Harry_Ph]

X. Xxxx was with X Corporation as a senior scientist. He is currently between positions.

What does the second sentence probably mean?
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The more we learn, the less we seem to know.

[Mister Micawber]

He's unemployed.
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Native English teacher at Mister Micawber's

[SkiIucK]

Now that's interesting! Thanks!

[Harry_Ph]

Oh, really? Thank you, Mister Micawber! This is the first time that I encounter it. Is it an idiomatic expression or what?
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The more we learn, the less we seem to know.

[Mister Micawber]

At leisure: adjective: idle; between jobs; (euphemism for `unemployed')
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Native English teacher at Mister Micawber's

[Harry_Ph]

Oh I see. Thank you very much, MM!
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The more we learn, the less we seem to know.