Surrounding — twice over. Circum- means around, and ambient comes from a root that also means going around, so the word says its own meaning and then says it again. This week’s A.Word.A.Day theme collects exactly that: terms with the repetition baked in, like pathway, which amounts to way way. Anu Garg calls it the Department of Redundancy Department, and notes that sometimes an old meaning faded until nobody heard the echo any more.