Is Double-Barrelled One or Two Words?

A double-barrelled gun has two barrels. A double-barrelled surname has two parts which are joined by a hyphen, for example ' Miss J. ...

Is it double barrel or double-barreled?

In the Western tradition of surnames, there are several types of double surname (or double-barrelled surname). If the two names are joined with a hyphen, it may also be called a hyphenated surname. The word "barrel" probably refers to the barrel of a shotgun, as in "double-barreled shotgun".

How do you spell double barrel?

having two barrels mounted side by side, as a shotgun. serving a double purpose or having two parts or aspects: a double-barreled attack on corruption.