A turn of phrase
Definition 1 of 2
Pro Tip 1/3Personal Flavor
Indicates the speaker's unique style or personality through words. 
His turn of phrase revealed a hint of his mischievous character.
Pro Tip 2/3Cultural Touch
May reflect the speaker's background, incorporating regional or cultural idioms. 
She used a Southern turn of phrase that had us all charmed.
Pro Tip 3/3Humor Injection
Can add wit or humor to a conversation or writing unexpectedly. 
His turn of phrase added a comical twist to an otherwise dry topic.