Word of the Week: Penumbra

Source: Oxford Dictionaries

Continuing from last week’s theme of the total solar eclipse, today’s Word of the Week features a related word also used as an astronomy term. While a small portion of the U.S. was in the path of the totality, most viewers were only able to see a partial eclipse at its peak. Still, the whole event was quite the experience, even for those of us who only got to view it from the “penumbra”!

“Penumbra” refers to the partially shaded outer region of the shadow cast by an opaque object, typically by the moon or the Earth during an eclipse. The word arose in the mid 17th century and is a modern Latin noun meaning “partial shadow”. This noun comprises two roots: the adverb paene “almost” and the noun umbra “shadow”.

Similar to “umbra”, “penumbra” can also be used as a different astronomy term for “the less dark outer part of a sunspot, surrounding the dark core”. The word can also function as a figurative term for an area of uncertainty between mutually exclusive states or an area on the edge of something. If you’re writing about an eclipse or want to refer to any sort of shadowy area, “penumbra” is a good word to consider for your stories!

What are your thoughts on this word? Any suggestions for future “Word of the Week” featured words?