敖 originally meant "to roam" — it appears in the Book of Songs 《
诗经》 in the line
以敖以游 ("to ramble and to roam"). It's a variant of
遨 (áo, to roam). It also denoted ancient granaries (
敖仓, the famous Qin-dynasty granary near modern Zhengzhou). Today most learners meet it as a surname.