In toto.—Altogether.

In transitu.—On the passage.

In utrumque paratus.—Prepared for either event.

In vacuo.—In empty space, or in a vacuum.

In vino veritas.—There is truth in wine.

Incognito.—Disguised; unknown.

Index expurgatorius.—A list of prohibited books.

Infra dignitatem.—Beneath one’s dignity.

Innuendo.—Covert meaning; indirect hint.