Prince William apparently calls Princess Charlotte this 'sweet' nickname

How sweet! Prince William appeared to call his middle child, Princess Charlotte, by an adoring nickname during the royal family’s recent visit to the Chelsea Flower Show in London. William and wife Kate Middleton took their three children to explore Middleton’s “Back to Nature” garden at the event.

In a video shared by Kensington Palace, the father of three can be seen interacting with his eldest son, Prince George.

“What would you give it out of 10? How many marks out of 10 would you give it — 10 being the highest?” he asked the 5-year-old.

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“Twenty!” the young boy replies.

“Twenty out of 10? That’s pretty good,” joked William in response, before adding, “I think mommy’s done well.”

“Mignonette?” William then asks, appearing to address Princess Charlotte.

“Yes?” the 4-year-old replies, before running to her father, who was on the rope swing, to “give [him] a push.”

Soon after, Twitter and Instagram users took to the respective social media platforms to address the sweet nickname, which is derived from the French word “mignon” which means “cute.” (Mignonette means “dainty” or “darling.”)

Though some people debated whether or not this was what Prince William really said in the video, others were quick to comment on the “lovely” nickname.

“Anyone notice right before he asked Charlotte to push him, he called her by her lovely nickname. Someone from [Kensington Palace’s Instagram] comment section suggested William called her ‘Mignonette’ which means ‘delicate,’" wrote one person.

“William is calling his daughter Mignonette! How sweet,” wrote a second.

“I think it’s mignonette… if that’s true how sweet is that?” commented another on Instagram.

“It’s a pretty common term of endearment in French,” wrote someone else.

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“Mignon is cute, I think, so it’s kind [of] like calling the child cutie,” said another.

The “Back to Nature” Garden was designed by Middleton as well as Andrée Davies and Adam White of Davies White Landscape Architects, award-winning landscape architects. The garden is meant to bring people together to “connect with nature,” the palace captioned their posts.

The garden features a swing, a treehouse made to look like a bird or animal nest, and a “multi-sensory, green and blue plant scheme,” a photo caption read.

Fox News' Ann Schmidt contributed to this report.