Definition of "composedly"

So far the letter had run composedly enough; but here, with a sudden splutter of the pen, the writer's emotion had broken loose.

1886, Robert Louis Stephenson, The Strange Case of Dr Jekyll and Mr Hyde

"You have this down to a fine art?" I said. "A girl needs to," she said composedly.

1958, A.G. Yates, The Cold Dark Hours, Sydney: Horwitz, published 1963, page 63