To make white or whiten; to bleach or lighten in color using whitening substances.
From 'be-' plus 'whiten.' The prefix 'be-' added emphasis to the action, so 'bewhiten' meant to thoroughly whiten something. This is an archaic or literary form.
In old texts, you'll see 'bewhitened tombs' and 'bewhitened brows'—the prefix gave a sense of theatrical emphasis perfect for poetry. It's like how 'be-' makes words sound more dramatic and formal.
Complete word intelligence in one call. Free tier — 50 lookups/day.