open
Not closed or blocked; allowing access or passage.
Etymology
Modern English open comes from Old English open "not closed, evident, public," from Proto-Germanic *upanaz, literally "turned up, put up," from PIE *upo meaning "up, up from under, over." The root idea is of something raised or lifted — an open door is one pushed upward or away. The same PIE root produced Latin sub "under" (from *upo with a shifted sense, giving English sub-, subject, substance, suffer) and Greek hupó "under, up from under." The apparent paradox of "up" and "under" sharing a root resolves when you realise *upo meant "up from below" — motion from under to over. German offen and Dutch open are Germanic siblings. The verb to open developed from the adjective. Within English, the same root appears in up itself, which is from PIE *upo, and in the prefix sub- through Latin — making open and submarine unlikely relatives.
The Journey: *upo → open
*upo
*upanaz
open
open
open
Cognates Across Languages
These words in other languages descend from the same PIE root *upo. They are not borrowings but independent inheritances from a common ancestor.
| Language | Word | Meaning |
|---|---|---|
| Latin | sub | under (from up from below) |
| Greek | hupó | under, up from under |
| Sanskrit | úpa | toward, near |
| German | offen | open |
| Dutch | open | open |
Did You Know?
Open and submarine share a PIE ancestor. Open comes from *upo "up from under" through Germanic (something lifted up), while sub- comes from the same root through Latin, where the meaning shifted to emphasise the "under" part. One word went up; the other stayed below.