Milo is most commonly considered to be Germanic name derived from the Latin word miles, meaning "soldier." However, there is evidence to suggest it also may have independently spawned from the Slavic root milu, meaning "merciful." Milo predates brother name Miles, a variation that evolved when the name immigrated to the British Isles in the Middle Ages. Mylo is an alternate spelling.

Quirky cool Arlo is now well and truly back. Last year it broke into the US Top 200 boy names and consistently ranks among the most popular boy names on Nameberry. Along with its Irish and English roots, Arlo may be a shortened form of the Italian Carlo or the Spanish Carlos, both forms of Charles,and in Basque-speaking regions it is the word for area.

Oscar is one of the most stylish Old Man Names of our era. While it's softened slightly in popularity over the past 20 years, that may be considered a very good thing.

Oliver is an international star, ranking near the top of the charts throughout the English-speaking world and in a host of European and Latin American countries, from Norway to Chile, Slovenia to Switzerland. Why? Because Oliver is energetic and good-natured, stylish but classic, with a meaning symbolizing peace and fruitfulness.

Hugo, the Latin form of Hugh, has more heft and energy than the original -- and of course we love names that end (or begin, for that matter) with an o. This one is especially appealing because it's backed up by lots of solid history and European style.

Owen, a resonant Celtic name, has ranked among the Top 100 boys' names in the US for 20 years and is now at its highest point ever.

Otto is cool again. Long a quintessential Old Man Name, Otto has been promoted to trending darling of adventurous baby namers.

Beau suggests someone devilishly handsome, with a large measure of southern charm—a nice image to bestow on your boy. Often solely a nickname in the past, it's now standing firmly on its own. Beau has been on the Social Security list non-stop since 1969.

Leo is a strong-yet-friendly name that was common among the Romans, used for fourteen popes, and is now at its highest point ever in the US thanks in part to Leonardo "Leo" DiCaprio.

See the popularity graph below for the name Theo? It's been heading straight uphill since 2010, when it hopped back onto the Top 1000 after a 60+ year absence.

With a touch of celestial power, a hint of clunky charm, and the totally cool -o ending, Cosmo may well be finally shaking itself free of both the Seinfeld association (which made it a punchline of a joke) and the cartoon fairy association from The Fairly OddParents. In fact, it is in the Top 1000 in the UK and a favorite on Nameberry.

Succinct, stylish, and catchy, Ivo has the energetic impact of other names ending in -o. It is a multicultural choice with two distinct origins, and, as such, is familiar across a variety of countries, ranging from the Netherlands to Brazil, from Portugal to Czechia.

Orion is a rising star, with both mythical and celestial overtones.

With mythological names rising, the handsome son of Zeus and god of medicine, music, and poetry among many other things might offer an interesting, and melodic option. Similar in style to Atlas and Atticus and similar in sound to Arlo, Paolo, Paul, and Ollie, Apollo entered the US Top 1000 back in 2012, and was propelled upwards after it was chosen by Gwen Stefani and Gavin Rossdale in 2014.

In the past, Orson has felt like a one-person moniker, tied to film director Orson Welles, who dropped his given name of George in favor of his more distinctive middle. While the Citizen Kane creator seemed to own the name during his lifetime, it's now an interesting possibility for any parent seeking an unusual yet solid name. It's started to appear to the celeb set too -- both Paz Vega and Lauren Ambrose have little Orsons.

This attractively energetic Italian version of the classic Matthew is primed to move further and further into mainstream American nomenclature. Mateo is technically the Spanish version, but many parents in the US use the two spellings interchangeably.

Cato conjures up images of ancient Roman statesmen and southern antebellum retainers; it could have revival potential, with its 'O' ending and the current interest in the names of Greek and Roman antiquity.

Odin is the name of the supreme Norse god of art, culture, wisdom, and law — who was handsome, charming, and eloquent into the bargain. The name projects a good measure of strength and power and has excellent assimilation potential.

Marlow is a suave, unusual surname-name that was chosen by Celine designer Phoebe Philo for her older son. This is a name with many spellings and many difference in gender identity. Marlowe is decidedly female, with only 10 percent of the babies named Marlowe male, while Marlow is 25 percent male, and Marlo is evenly divided.

Tough-yet-cuddly Bruno is an international name even in its origins: it derives from the Germanic word for "brown" plus a Latin ending, and was borrowed as a color word in many European languages.