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Home › Baby Names Directory › Casi

Casi

♀ Girl

How to Pronounce Casi

Pronounced KAY-see /ˈkeɪ.si/High

Meaning: Casi is a trimmed respelling of Casey — from the Irish surname Ó Cathasaigh, meaning 'vigilant' or 'watchful' — and it also reads as a form of Cassie, a short form of Cassandra. The spare spelling gives the name a bright, modern look.Low

In 30 seconds: Casi is a respelling of Casey/Cassie, from an Irish surname meaning 'watchful.' It crested in the late 1980s.
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Origin LowIrish
MeaningCasi is a trimmed respelling of Casey — from the Irish surname Ó Cathasaigh, meaning 'vigilant' or 'watchful' — and it also reads as a form of Cassie, a short form of Cassandra. The spare spelling gives the name a bright, modern look.
U.S. rank (2022)#15763 ↘ Falling
2022 U.S. births5 girls (0.00% of U.S. girls)
Peak year1989
Total births (all-time)≈ 1,080

Popularity in the U.S. · SSA data

peak 198919622022

U.S. births per year (Social Security Administration, 1880–present). Pink marker = peak year.

SSA data updated May 2026. How we source & verify this data.

History & Origin

Casi is a phonetic respelling of Casey, which comes from the Irish surname Ó Cathasaigh, meaning 'vigilant' or 'watchful'; it also overlaps with Cassie, a diminutive of Cassandra. As Casey grew popular for girls in the 1980s, the streamlined Casi spelling followed, cresting in the late 1980s.

Casi stayed uncommon, borne by a modest number of girls before easing back in the 2000s. A Casi from her peak is now in her thirties. The name reads as a bright 1980s respelling and has not stood out on its own, though Casey remains familiar for both sexes.

Did you know? Casi rode the 1980s vogue for unisex Casey while trimming it to a crisp, four-letter girls' form — one of many short, phonetic spellings that decade favored.
Overall data confidence 50%
References — Casi — respelling of Casey/Cassie; Irish Ó Cathasaigh 'watchful'; Cassandra

Variations

CaseyKaciCassi

Nicknames

Cas

Famous Bearers

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If you like Casi…

Casey— the base name this respells
Kaci— a like phonetic spelling of the same name
Cassie— the Cassandra short form it overlaps
Macy— a same-era bright girl's name of the period

Explore names like Casi

By themerespellingirish1980s

All themes →All meanings →All origins →

Frequently Asked

What does the name Casi mean?

Casi is a form of Casey, from an Irish surname meaning 'vigilant' or 'watchful'; it also overlaps with Cassie, from Cassandra.

How do you pronounce Casi?

It's said KAY-see /ˈkeɪ.si/ — two syllables, stress on the first.

Is Casi a boy or girl name?

Casi is used as a girl's name.

How popular is Casi?

Casi was an uncommon respelling of Casey that crested in the late nineteen-eighties and then eased back.

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