Sibling names for Cynthia
Names that sound like they belong in the same family as Cynthia usually share its era. These sister and brother names rose and fell on a similar curve to Cynthia, whose busiest decade was the 1950s, and are about as common, so neither child's name will feel dated or unusual next to the other.
Sister names for Cynthia
| Name | Meaning | Rank 2025 | Babies, last 5 years | Peak decade |
|---|---|---|---|---|
| Pamela | coined by Philip Sidney (meaning unknown) | #2,251 | 479 | 1950s |
| Kathy | pet form of Katherine or Kathleen | #3,274 | 319 | 1950s |
| Denise | feminine of Dennis (Dionysius) | #1,677 | 736 | 1960s |
| Lynn | lake or pool (surname) | #2,558 | 303 | 1950s |
| Karen | Danish form of Catherine | #1,281 | 1,015 | 1950s |
| Teresa | #911 | 1,589 | 1960s | |
| Sheila | #2,686 | 506 | 1960s | |
| Brenda | #1,527 | 915 | 1950s | |
| Susan | lily (from Susanna) | #1,091 | 1,099 | 1950s |
Brother names for Cynthia
| Name | Meaning | Rank 2025 | Babies, last 5 years | Peak decade |
|---|---|---|---|---|
| Randy | pet form of Randall or Randolph | #1,089 | 1,158 | 1950s |
| Rick | short form of Richard; "strong ruler" | #3,077 | 216 | 1950s |
| Mark | #245 | 7,106 | 1960s | |
| Terry | from Thierry (Theodoric); or short for Terence, Theresa | #1,116 | 1,015 | 1950s |
| Gregory | watchful, alert | #593 | 2,828 | 1960s |
| Steven | crown, wreath (form of Stephen) | #271 | 6,813 | 1950s |
| Douglas | black stream | #807 | 1,595 | 1950s |
| Darrell | from d'Airel (Norman place name) | #1,691 | 588 | 1960s |
| Keith | wood (Scottish place name) | #801 | 1,873 | 1960s |
| Rodney | Hroda's island | #1,093 | 1,044 | 1960s |
Cynthia's era
Cynthia ranked #1,014 for girls in 2025, against #540 in 2015. Its best year was 1957, at #7. Names that rose and fell with it share its period feel, which keeps the set consistent.
Timeless names that go with any sibling
These names have been used steadily for a hundred years, so they sit comfortably next to a name from any era, Cynthia included.
Girls: Elizabeth, Miriam, Nina. Boys: Samuel, Anthony, Wesley, Vincent, Victor, Oscar.
Same era, but close to Cynthia
These names follow Cynthia's curve too, but we left them out above because they share a first letter or an ending with Cynthia. Some parents like that echo; if you do, start here.
How these were chosen
Each suggestion's share of US babies has followed a curve close to Cynthia's since 1880, and its recent number of babies is within about twelve times Cynthia's, so the names are in the same league. Names starting with the same letter as Cynthia or with the same ending are left out, so the names go together without matching. Spellings of Cynthia itself are excluded.