penumbra

1. 1.

   a fringe region of partial shadow around an umbra

   Broadershadow

Other forms of penumbra

plural

penumbrae

Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.

Questions about penumbra

What does penumbra mean?

penumbra means "a fringe region of partial shadow around an umbra".

How many syllables are in penumbra?

penumbra has 3 syllables: pe-num-bra. The stress falls on "num". In IPA it is /pɪˈnʌmbɹə/.

Is penumbra a common word?

penumbra is banded "Rare" — specialist or archaic — most readers will not have met it. The band comes from how often the word appears in a large corpus of everyday English, not from an editor's impression.