The verb itself is almost never used in every day English, but there are two adjectives formed from it which are common:
- "scathing" means extremely harsh, biting, critical; e.g. "he launched into a scathing attack on his opponent's policies"; "the review was scathing in its criticism"
- "unscathed" means "unharmed"; e.g. "despite the dramatic accident, he escaped unscathed"
I would classify both of these as a kind of "fossil" - although clearly derived from the present and past participles of "to scathe", they are used only as distinct adjectives.
"Unscathed" has the additional distinction of being an "unpaired word" - although it should logically be the opposite of "scathed", that word is rarely used except in deliberate word play. It would be more natural to say "was nearlyalmost unscathed" or "was not unscathed" than "was barely scathed" or "was scathed".