From the Old Norse, we received the adjective "scant" and the adverb "scantily." We make scanty use of either and, when we use them at all, we seem to use them in very narrowly defined situations. About the only place I see "scant" used is in cooking instructions, e.g. add a scant teaspoon of arsenic or dried bat wings or somesuch. About the only place I see "scantily" used is in reference to people (or women, more precisely) who are not wearing much, described as "scantily clad." Why is this?

Hi Father Steve,
With your phrase to use them in very narrowly defined situations in fact you nearly answer your question yourself: scant(y) covers such a small stretch between "too little" and "enough" (not including those boundaries), that opportunity for it's use rarely arises. Large expanses prevail on either side of it's domain.

Well, the first 30 hits from Google agree with you for scantily. They are all scantily clad or scantily dressed --mainly women, but also two for men, and one for a little boy.

The results for scanty are skewed by the presence of two pop groups Scanty Sandwich and The Scanty. However I did find this gem about a cactus: This wood has scanty paratracheal parenchyma. I'm surprised this example didn't immediately spring to mind.

Scant on the other hand seems to occur with lots of different nouns: reward, hope, prospects, salary, regard, respect, growth, progress, evidence.

Bingley

Only rant
is
never scant.

scanty use

I would say scant use. In fact, "we made scant use" has always been something of an idiom to me. We bought the fertilizer, but we made scant use of it. Don't think I've ever heard or used scanty use.