If it's not capitalized (turned into an asset) then it's not an investment from an accounting perspective. Although R&D may be considered an investment by the layman, as the OP pointed out:

>even if it can be defined as investment in layman terms.

Spent: verb, to spend, you could spend money settling a lawsuit but it would be a stretch to call that investment.

Investment: to allocate money in the expectation of future benefit, so that could mean administrative expenses, which would cover and include a lot (but not all) spending.

My vote would be on invested.