hold onto your hat

== English == === Alternative forms === hold on to your hat === Pronunciation === === Phrase === hold onto your hat (idiomatic, usually humorous) One should prepare for a surprise or shock. Synonym: hang onto your hat Used other than figuratively or idiomatically: see hold,‎ onto,‎ hat. ==== Usage notes ==== When addressing a group, the plural is used: hold onto your hats. === References === “hold on to your hat”, in OneLook Dictionary Search.