"Contemporary" vs. "contemporaneous"
What is the difference between these two words?
contemporary: From the same time period, coexistent in time.
contemporaneous: Existing or created in the same period of time.
I know that contemporary has a second meaning (modern), but I'm asking about the above sense. Can they be used interchangeably?
Solution 1:
Contemporary and contemporaneous both mean originating, existing, or happening during the same period. But although these adjectives are close in definition, they’re used slightly differently.
Contemporary usually applies to people or small groups of people. For example, the Beatles and the Beach Boys were contemporary with each other because they were active at roughly the same time. Contemporaneous usually applies to events, movements, or trends. For example, the rise of rock music was contemporaneous with the economic boom and counterculture movements of the 1950s and ‘60s.
The definition of contemporaneous is narrow, confined to this one sense. Contemporary is broader; sometimes it means current or modern, and it’s also a noun denoting a person who exists at the same time as another.
Examples
These writers demonstrate correct usage of contemporary:
The gallery began collecting contemporary works, mainly through Britain, which understandably remained our window on to the world of art . . . [Australian]
Vermeer and Metsu were contemporaries, but Metsu was the star in the Golden Age of Dutch painting during the 17th century . . . [NPR]
The three-way race nicely illustrates the tensions within the contemporary GOP. [Telegraph]
And these writers use the less common contemporaneous correctly:
The change in the holiday was contemporaneous with a larger change in attitude among many American toward their government . . . [Taunton Daily Gazette]
This point is underlined at the exhibition by the inclusion of contemporaneous works of rivals such as Kitagawa Utamaro. [Japan Times]
They judge the past not by contemporaneous standards but by their own politically correct notions . . . [Washington Examiner]
[Resource: grammarist.com]
Solution 2:
When not used to mean "modern," contemporary is usually used as a noun, meaning one that was (or is) alive or active at the same time as another: "Shakespeare's contemporary, Christopher Marlowe, is not as well remembered today." Contemporaneous is never used in this way; it is always an adjective.
As you note, contemporary as an adjective can mean both "modern" and "from the same time period [as another]," whereas contemporaneous only takes the second definition. Contemporaneous works about the 16th century were written and/or published in or near the 16th century, whereas contemporary works about the 16th century were probably published recently (although not necessarily; there is potential for ambiguity here).