According to MerriamWebster US catch phrase as two words is incorrect It should only be spelled as catchphrase The Cambridge dictionary UK agreesAs Wiktionary is a dictionary edited by anyone and not of the stature of either Webster or Cambridge Wiktionarys use of catch phrase as the primary form and catchphrase as an alternative form similarly the Wikipedia article Catch phrase would seem to be incorrectPersonally I think that the Wikipedia article should be changed from Catch phrase to Catchphrase in keeping with both American and British authorities Then an editor should use AWB to globally change the spelling throughout Wikipedia from catch phrase to catchphrase Thats my  worth