The Duke and Duchess of Cambridge will give their third child a "traditional but down-to-earth" name.

The Duke and Duchess of Cambridge

The Duke and Duchess of Cambridge

The royal couple announced they were expecting another baby earlier this month and, since then, betting sites have been crazy trying to predict the unborn royal's moniker but Christian Turner, global naming director at Siegel+Gale, thinks the pair will opt for something that carries some "weight."

Speaking to HELLO! magazine, he said: "The key consideration when naming a royal baby is the fine balance between tradition and accessibility. The Duke and Duchess of Cambridge will want the fifth-in-line to the throne to bear a name worthy of such weight, and it's therefore likely they will choose a solid, traditional name with strong links to royalty. At the same time, they won't want to appear old-fashioned or haughty, so choosing a name the public can embrace is equally important."

It's not yet known whether the pair are expecting a little boy or girl but they'll no doubt want a name that fits well with their four-year-old Prince George and two-year-old daughter Princess Charlotte.

Mr. Turner explained: "George and Charlotte are excellent examples of names that strike the balance perfectly; royal by tradition, solid in heritage, both names have enjoyed a resurgence over the last decade, and it's not uncommon to hear either name being called in the local playground. This is common of the style of this generation of royals, who want to be more down-to-earth."

The duke and duchess, both 35, were forced to announce their baby news last week after the brunette beauty pulled out of a royal engagement due to Hyperemesis Gravidarum - a debilitating form of serious morning sickness - which she suffered with during her two previous pregnancies.

Kensington Palace said in a statement: "Their Royal Highnesses the Duke and Duchess of Cambridge are very pleased to announce that the Duchess of Cambridge is expecting their third child. The Queen and both their families are delighted with the news."