stilted

The adjective stilted describes something—usually a style of writing or speaking—that is unnaturally formal.

Imagine someone walking awkwardly on a pair of stilts and you have a good impression of the word stilted — wooden and stiff. Stilt is found in the mid-15th century, referring to walking on wooden stilts across marshy ground. A hundred years later, the word stilted came to refer to the posts holding up a building. It wasn't until 1820 that the word was used as we use it now, to describe writing or speaking that does not flow smoothly.