In a manner relating to the face or facial features; with respect to facial appearance or expression.
From 'facial' (adjective relating to the face) plus the -ly suffix that converts adjectives to adverbs. 'Facial' comes from Latin 'facies' (face).
The term 'facially' is rarely used in everyday speech, but in fields like medicine and psychology, distinguishing 'facially similar' features from other characteristics can be scientifically important!
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