といえども

といえども means "even": the person or thing before it is the kind you would expect to be an exception, and the rest of the sentence says it is not. It follows a noun directly, with no particle in between, or a plain-form clause. 言えども is the old concessive form of ゆう言う, and the pattern belongs to formal writing and speeches; in conversation the same idea is でも or といっても.

The second half goes against what the first half leads you to expect, so it is usually a negative, an obligation (なければならない, べきだ) or "it happens even so". A second half that simply follows from the first does not fit.

• × プロといえども、上手だ → プロといえども、失敗することはある

Conceding a fact

After a clause, or a noun that describes the situation, といえども grants that something is true and says it does not change the outcome: "it may be X, but".

Usage notes

These go beyond a noun on its own.

With たとえ and いかに

Even a little

After one, or a small amount, といえども means "even so little". The sentence then says it still counts.