Tamsin
Meaning: “Twin (Cornish form of Thomasina)”
About the name Tamsin
Tamsin is a girl name with Cornish roots, meaning “Twin (Cornish form of Thomasina)”. It is related to Thomas, which is where the meaning comes from.
It has a unique feel. Fewer than 5 US babies of either sex received it in 2025, so it's very rare right now. Its peak year since 1940 was 2017. Since 2000, 100% of US babies named Tamsin were girls.
Etymology
A feminine form of Thomas, which comes from Aramaic, meaning “twin”.
Name meaning adapted from Wiktionary (“Tamsin”, “Thomas”) by Wiktionary contributors, CC BY-SA 4.0.
- US rank 2025
- Not ranked
- In 2015
- #6013
- Babies in 2025
- Under 5
Popularity of Tamsin, 1940–2025
Latest SSA data: 2025.
Popularity data: U.S. Social Security Administration national baby names (public domain; names given to at least 5 babies of one sex per year).
Nicknames for Tamsin
- Tammy
Names similar to Tamsin
Name meanings marked or linked “Wiktionary” are adapted from Wiktionary by Wiktionary contributors, CC BY-SA 4.0; each name page links its source entry.