Modesty. Alsong with "chastity," "obedience" and "Chick-Fil-A," it's one of the Duggars' favorite words.
Usually, it refers to the infamous Duggar dress code, which dictates that the ladies of the family should basically be as covered up as possible at all times.
But flashing some ankle isn't the only way to draw some attention to yourself.
Michelle and Jim Bob's daughters are also discouraged from behaving of presenting themselves in ways that might make them appear ostentatious or -- in the parlance of the times -- "thirsty."
(It may seem strange for a bunch reality TV stars to be so concerned with keeping a low profile, but the Duggars are nothing if not hypocritical.)
So you can be certain that JB is none too thrilled about Jinger Duggar's latest look.
Yes, the 25-year-old is now the sole blonde in a family of brunettes.
"Decided to go with the blonde balayage this Summer," she captioned the photo above.
Several of her famous family members have been supportive of Jinger's decision to lighten her locks:
"Spurgeon saw this pic and said 'She turned her hair gold!' Looks lovely, Jinge!" wrote Jessa Duggar.
"You are gorgeous!" Anna Duggar.
Interestingly, both Jim Bob and Michelle have yet to comment on the major change in Jinger's appearance.
While Duggar women are permitted to wear makeup and jewelry, major alterations to one's appearance are generally frowned upon.
And going blonde is certainly not Jinger's only act of rebellion in recent months.
As you're probably aware, Jinger's decision to start wearing shorts after marrying Jeremy Vuolo amounted to a major violation of the family dress code and cemented her place as the Duggar's resident rebel.
Just as it looked like Jim Bob and Michelle were coming to terms with that act of defiance, Jinger announced another decision that her parents are less than thrilled with.
Along with her husband and daughter, Jinger will be moving to Los Angeles next month so that her husband can study at an area divinity school.
“In recent days, God has made it overwhelmingly clear to us that he is leading us out of Laredo," the couple recently wrote in a statement.
"Through much prayer and counsel, the next step for our family is to relocate to Los Angeles to attend Grace Community Church as Jeremy pursues graduate studies at The Master’s Seminary,” they added.
“As excited as we are to begin this new adventure, leaving Laredo this July will be one of the hardest things we’ve ever done; our friends here have become like family.
"Please pray for us as we open this new chapter of our lives.”
Attending divinity school may not seem like the most rebellious act, but you can be sure the Duggars' aren't thrilled with their daughter residing in one of the most liberal cities in the country.
And now she'll be blonde in Los Angeles!
They're probably admonishing her to stay far away from subway grates and Marilyn Monroe-style skirts at this very moment.
Scandalous stuff, folks!