NOTE: As Tiffany, Sunny and Jessica were all given both English and Korean names, I have researched their names in both languages.

Taeyeon (Kim Tae-yeon): 金太軟

Tae > 太 (클 태): Big, large

Yeon > 軟 (연할 연): Soft, tender

Overall meaning: Grow big, but be soft

Sunny

English: Susan Soonkyu Lee

Susan: Lily

Korean: Lee Soon-kyu (李純揆)

Soon > 純 (순수할 순): Pure, genuine

Gyu > 揆 (헤아릴 규): To estimate

Overall meaning: To estimate purity

Tiffany

English: Stephanie Young Hwang

Stephanie: Garland/Crown

Korean: Hwang Mi-young (黃美英)

Mi > 美 (아름다울 미): Beautiful

Young > 英 (꽃부리 영/뛰어날 영): A flower petal/Heroic

Overall meaning: A beautiful flower petal

Hyoyeon (Kim Hyo-yeon): 金孝淵

Hyo > 孝 (효도 효): Filial duty