A term coined by Arthur Quiller-Couch in a series of lectures (On the Art of Writing) he gave in 1916. The full quote is above.
‘Murdering your darlings’ refers to deleting every word that isn’t pertinent to the story, even those words or phrases that you’ve grown to love. It’s not at all easy to do, but I do believe it’s all about non-attachment and losing your ego!
I used to read and reread little phrases I’d included in stories, thinking how wonderful they were, but I look back at them now and cringe as they are real examples of ‘purple prose,’ aka navel-gazing rubbish! If I’ve learned anything over the past few years, it’s to pare down the message to what really needs to be said. The purpose of writing a story is not to show the world how great your lexicon is, it’s to tell a story that people relate to and by using pompous vocabulary and taking twenty words to say something that can be said in five, the message is diluted and a chance for meaningful communication lost.