Can you *donate* to a non-charitable cause?

Solution 1:

A donation is a voluntary gift or contribution for a specific cause.

That cause does not have to be a charity, a political donation is still a donation, it is a gift for a fund of some description. There may be restriction on the use from an accountancy perspective in certain parts of the world, but not from a linguistic perspective.

Solution 2:

Donation comes from latin, dono, -are. to give, or donum, doni, n., gift (in general). Thus, I doubt it's restricted to charities.

Solution 3:

Tax expert here. At least in America, "donation" and "charity" are linked because only charities get favorable tax treatment. They don't pay taxes, and your donation is tax deductible. You donate $100 and your taxes drop by $40, net cost to you is $60. So it rankles Americans to call it a "donation" when they can't take a tax deduction.

Contrast with the UK, where there is no tax advantage to donations, charity or not. However the government will match your gift to a charity, amplifying the power of your gift. You donate $60 and the government donates another $40. It's the same effect but a very different mechanism, leading to different thinking.