umbrage: [15] Umbrage is one of a group of English words that go back ultimately to Latin umbra ‘shadow’. Indeed, it was originally used for ‘shade, shadow’ in English: ‘the light, and also … the false umbrage which the moon doth show forth’, Betham, Precepts of War 1544. The expression take umbrage ‘take offence’ arises from a metaphorical extension of ‘shadow’ to ‘suspicion’, which took place in French.
The word itself reached English via Old French umbrage from Vulgar Latin *umbrāticum, a noun use of the neuter form of Latin umbrāticus ‘shadowy’, which was derived from umbra. Other English words from the same source include adumbrate [16], penumbra [17], sombre, sombrero, umbel [16], and umbrella. => adumbrate, penumbra, sombre, sombrero, umbel, umbrella
umbrage (n.)
early 15c., "shadow, shade," from Middle French ombrage "shade, shadow," from noun use of Latin umbraticum "of or pertaining to shade; being in retirement," neuter of umbraticus "of or pertaining to shade," from umbra "shade, shadow," from PIE root *andho- "blind, dark" (cognates: Sanskrit andha-, Avestan anda- "blind, dark"). Many figurative uses in 17c.; main remaining one is the meaning "suspicion that one has been slighted," first recorded 1610s; hence phrase to take umbrage at, attested from 1670s.