Decimus

#9,105 in 2025Boys' name

Tenth

Decimus has been given to 67 babies in the U.S. since 2006. In 2025 it ranked #9,105 of 13,926 boys’ names in use. Its peak year was 2006, with 8 recorded.

Babies named Decimus, 2025

1 in 414,000

Decimus over time, 1880–2025

Boys

Based on births in the U.S. Babies given the name each year. Hover the chart — or focus it and use the arrow keys — for any year. Gaps mean the name was given fewer than 5 times that year; these counts are unpublished.

Decimus: meaning, origin, and history

Tenth

Deeper origin not confirmed in the cited records

What Decimus means

Decimus means “tenth”.

American usage and historical context

In the United States, 67 boys were recorded with the name Decimus between 2006 and 2025. Its highest annual count was 8 in 2006; its best national rank was #8,898 in 2006.

Over 5 years its rank rose, from #12,478 in 2020 to #9,105 in 2025. Over 10 years its rank rose, from #9,787 in 2015 to #9,105 in 2025.

Sources & methodologyReferences, data & attribution

Meaning, origin, and language notes draw on the references below.

American popularity figures use published Social Security Administration records for this exact spelling. Counts below five for a name, sex, and year are omitted.

U.S. Social Security Administration: national name data and limitations

How common is Decimus?

Everything below is computed from the 2025 data — the most recent year available.

Among all babies, 2025: 1 in 414,000; 8 of 3,315,165 births
Among boys only: 1 in 213,000; <0.01% of boys
Rank, 2025: #9,105; of 13,926 boys’ names in use
Coin-flip room size: 287,238 kids; Even odds of a second one

Where Decimus sits on the popularity scale

Rarest published (5 a year)#1 — Liam (20,818)

Chance at least one other child shares the name

If the other children were drawn at random from the 2025 national name distribution. Real classrooms cluster by region and community, so treat these as a floor, not a ceiling.

Class of 20Under 1%

Class of 30Under 1%

Grade of 100Under 1%

School of 500Under 1%

Put another way: gather 287,238 children born in 2025 and it's an even bet that one of them is another Decimus. In a class of 30 the chance is Under 1%.

When Decimuss were born

Half of everyone ever recorded as Decimus was born before 2014 — so the typical Decimus is around 11 today.

Median birth year: 2014; About 11 years old
Biggest decade: 2010s; 49.3% of all use
Born in the last 25 years: 100.0%; A modern name
Recorded since 1950: 67; People you could plausibly meet

Choose a decade

2010s — 49.3% of all recorded uses (33).

Is Decimus rising or falling?

Rank movement and count movement can disagree — the number of distinct names in use keeps growing, so a name holding a steady count still slides down the list. Both are shown.

Rank vs 1 year ago: —; Not ranked then
Rank vs 5 years ago: +3,373; Places climbed
Rank vs 10 years ago: +682; Places climbed
Births vs 10 years ago: 1.14×; More babies than then
Share of its own peak: 100.0%; Peak was 2006 (8)
Years since peak: 19; Years
Year-to-year steadiness: Shifting; 23.5% average annual change
Best rank ever: #8,898; 2006

Spellings of Decimus

Decimus is not the most common spelling — Delmus is, with 48.9% against Decimus's 5.5%.

Delmus48.9%599
Derius45.7%560
Decimus5.5%67

Grouped by closeness of spelling (up to two letter changes), same sex, with a floor on all-time use. It catches Sophia/Sofia and Aiden/Ayden, and misses spellings that sound alike but look different, like Sean and Shawn.

Decimus around the world

Where Decimus ranks in official birth records elsewhere in the world. Rankings only — the number of births isn’t comparable between places, so it isn’t shown.

South Australia
2009–2009
#708
in 2009

Popularity data from Consumer and Business Services (South Australia). CBS SA data under CC BY 4.0.

Decimus by the numbers

The raw record for each sex the name is used for.

As a boy's name

Rank in 2025: #9,105
Trend vs 5 yrs ago: Up 3,373
Best rank ever: #8,898; 2006
Peak year: 2006; 8 that year
First recorded: 2006
Last recorded: 2025
All-time count: 67
Count in 2025: 8

Names similar to Decimus

Matched on shared beginnings and endings, similar length, and comparable popularity.

Declen Decarri Dechlan Decklen Deckard Decatur Artimus Decklyn Decari Decorey Decland Decklan Decorion Decoda Declin Declynn Decory Decklin Decota Shaymus Declyn Chalmus Rasmus Erasmus

Sibling names for Decimus

Names from the same era and popularity tier — the two things that make a sibling set feel deliberate — skipping lookalike spellings and shared initials.

For a sister

Abagail Jazmyne Shakira Taniya Rhianna Madisen Sydnee Lesli

For a brother

Aaden Kale Keven Jarod Zakary Nathen Garret Samual

Explore around Decimus

Top names of 2006, Decimus's peak year The 2000s in full Other names that peaked in 2006 Boys' names starting with D