Some screenwriters refer to these as the ‘third track’ of dialogue (with the first two tracks being ‘melody’ and ‘harmony’.

Key words, phrases, taglines, and sounds are the third track of dialogue. These are words with the potential to carry special meaning, symbolically or thematically, the way a symphony uses certain instruments, such as the triangle, here and there for emphasis. The trick to building this meaning is to have your characters say the word many more times than normal. The repetition, especially in multiple contexts, has a cumulative effect on the audience.

— John Truby, Anatomy of Story

We all know people in real life who […] use a series of jingles and tags and repetitive gestures to maintain a certain kind of performance.

— James Wood, How Fiction Works

A variant on the arc phrases also occurs in a lot of middle grade fiction.

Key Words and Phrases In The Narrative Voice

In Once by Morris Gleitzman the arc phrase word involves the word Once, which explains the significance of the title.

Everybody deserves to have something good in their life. At least once
Barney said that everybody deserves to have something good in their life at least once. I have. More than once.

Related to arc phrases are ‘catch phrases’.

The hero of Once is in a dire situation — he is a Polish kid in the Nazi era, dodging murder at every turn. It would be easy for this story to turn into a sob story, so Gleitzman has him use the phrase, “You know how…” whenever he’s telling the reader something terrible about his life.

The first example occurs at the third sentence of the book, and these situations he describes only get more and more dire:

You know how when a nun serves you very hot soup from a big metal pot and she makes you lean in close so she doesn’t drip and the steam from the pot makes your glasses go all misty and you can’t wipe them because you’re holding your dinner bowl and the fog doesn’t clear even when you pray to God, Jesus, the Virgin Mary, the Pope and Adolf Hitler?
That’s happening to me.

Likewise, Millions by Frank Cottrell Boyce was written concurrently with the screenplay. Both the screenplay and the book came to fruition, my point being that the book was the first written by an experienced writer of screenplays. Naturally Cottrell Boyce made use of all he knew about screenplays when writing the middle grade novel.

In this book, the first person storyteller narrator repeats the phrase, “To get X about it…

 

An Unusual Phrase Associated With A Character

Sometimes the main character has a distinctive phrase rather than, as in the above examples, the (first person) narrative voice.

Judy Moody (series written by Megan McDonald) has a catch phrase — I don’t know if it’s a regional dialect but I’ve never heard it before: “Rare!” My seven-year-old started using this word only after reading it in Judy Moody, though she did use it in the general way rather than in the Judy Moody way, as an exclamation.

Joan Aiken’s raven, Mortimer, squawks “Nevermore!” in reference to the classic poem, which is funny because the stories are slapstick humorous whereas the poem is gothic horror. Apart from making squawk type sounds this is the only word he knows. Aiken adroitly contrives a surprising number of occasions in which he can use it.

 

Unintentional Pop Culture Spoofing

Chances are that looking back on your childhood experience of reading Enid Blyton’s Famous Five series, you remember ‘lashings of‘ in reference to the picnics — lashings of cream, lashings of butter, lashings of ginger beer. If you happen to re-read those books the word ‘lashings’ doesn’t actually appear all that often. But for some reason it stuck! Helped along by Comic Strip Presents… Five Go Mad In Dorset parody. ‘Lashings’ became part of pop culture mostly as a derisive comment on Blyton’s unimaginative prose, I suspect (she could pump these out one per week). I’m sure this spoof does the popularity of the series no harm.

Still, writers are often warned against word echo, which means writers shouldn’t use a particular ‘word with personality’ more than, say, once in any novel length work otherwise the word calls attention to itself. As Blyton’s ‘lashings’ demonstrates though, even (possibly) unintentional overuse of a word can become part of its enduring popularity.