9 Q Without U Words for Words With Friends
1610s, "action of excavating," from Latin excavationem (nominative excavatio) "a hollowing out," noun of action from past participle stem of excavare (see excavate).
excavation ex·ca·va·tion (ěk'skə-vā'shən)n.
A natural cavity, pouch, or recess.
A cavity formed artificially or as the result of a pathological process.