um·bra / ˈəmbrə/ • n. (pl. -bras or -brae / -ˌbrē; -ˌbrī/ ) the fully shaded inner region of a shadow cast by an opaque object, esp. the area on the earth or moon experiencing the total phase of an eclipse. Compare with penumbra. ∎ Astron. the dark central part of a sunspot. ∎ chiefly poetic/lit. shadow or darkness.DERIVATIVES: um·bral adj.

umbra phantom, ghost XVI; uninvited guest accompanying an invited one; (astron.) shadow XVII. — L. umbra shadow, shade, phantom, etc.