Definition of "sharer"

[…] the true gamesters pretended to be ill, and refused their glass, while they plied heartily two young fellows, who were to be afterwards pillaged, as indeed they were without mercy. Of this plunder I had the good fortune to be a sharer, though I was not yet let into the secret.

1749, Henry Fielding, Tom Jones

He was densely distressed—and perhaps I should have sympathized with him if I had been able to detach my mental vision from the unsuspected sharer of my cabin as though he were my second self. There he was on the other side of the bulkhead, four or five feet from us, no more, as we sat in the saloon.

1909, Joseph Conrad, The Secret Sharer

Job sharers find that they can approach the job in a fresher and more positive manner because they are only working for a part of the week, as opposed to a complete week.

2017, Jonathan Sutherland, Key Concepts in Business Practice