avast \əˈvast, -aa(ə)st, -aist, -ȧst\verb imperative Etymology: perhaps from Dutch houd vast hold fast, stop, from houd (imp. of houden to hold, stop, from Middle Dutch) + vast fast, from Middle Dutch; akin to Old High German haltan to hold and to Old English fæst fast — more at hold, fast : a nautical command to stop or cease < avast heaving > < avast lowering >