What is the X in X-mas?
Old English scunian "to shun, avoid; abhor; desist, abstain; to hide, seek safety by concealment," of uncertain origin; not found in any other language. Perhaps ultimately from PIE root *skeu- "to cover, to hide." Related: Shunned; shunning. A shun-pike (American English, 1911) was a road constructed to avoid tolls.