In a family, a sibling was an offspring born from the same parent or parents as another offspring. (DS9: "Family Business") In the case of multiple births, more than one sibling (i.e. twin, triplet, or quadruplet) were born at one time. (DS9: "Vortex", et al.)
Trill symbionts had to move on from their previous hosts' lives, even forgetting any siblings the host may have had. (DS9: "Rejoined")
In 2153, Doctor Phlox asked T'Pol if she had any siblings. This was done as a prelude to soliciting her help with Trip Tucker, who was grieving the loss of his sister Elizabeth in the Xindi incident. (ENT: "The Xindi")
Haliz recruited Kazon to be fighters as soon as they were old enough to protect their younger siblings. (VOY: "Initiations")
As of 2374, the crew of USS Voyager knew little about Annika Hansen, such as whether she had any siblings. (VOY: "The Gift")
Siblings
Brother
The male sibling was known as the brother. (TOS: "What Are Little Girls Made Of?", et al.) In the Ferengi language, the term was translated as "yoba". (DS9: "Little Green Men")
A child who has a brother shared through one parent was known as a half-brother. Spock and Sybok were half-brothers; both were sons of Sarek, but both had different mothers. (Star Trek V: The Final Frontier)
Sister
The female sibling was known as the sister. (Star Trek II: The Wrath of Khan, et al.) A sister who was not biologically related but rather by marriage was known as a stepsister. (TNG: "Parallels", DS9: "The Magnificent Ferengi") Ships that were similar to each other were, in keeping with the tradition of referring to a ship as a "she", known as sister ships.
Examples
List of full siblings
- List of full siblings:
- Beautiful Flower, Jana, Dahj Asha, and Soji Asha
- Ezri Dax, Janel Tigan, and Norvo Tigan
- Demmas and Ameron
- Duras, Lursa, and B'Etor
- Kahless and Morath
- Karden and Kinell
- Kathryn Janeway and her sister
- Kira Nerys, Kira Reon, and Kira Pohl
- George Samuel and James T. Kirk
- Geordi and Ariana La Forge
- Travis Mayweather, Paul Mayweather, and their sister
- Meribor and Batai
- Narek, "Narissa Rizzo", and their brother
- Neelix and Alixia
- Molly and Kirayoshi O'Brien
- Obrist and his brother
- Robert and Jean-Luc Picard
- Jake and Willie Potts
- Quark and Rom
- Devinoni Ral and his four siblings
- Malcolm and Madeline Reed
- Connor Rossa and his brother
- Seska and her brother
- Judith Sisko and her two brothers
- Simon Tarses and his brother
- Kestra and Deanna Troi
- Lwaxana Troi and her sister
- Thaddeus and Kestra Troi-Riker
- Charles and Elizabeth Tucker
- Vel and Piri
- Worf and Kurn
- Natasha and Ishara Yar
- Yranac and his sister
- Zeus and Hera
List of multiple birth siblings
- List of multiple birth siblings:
- Ah-Kel and Ro-Kel
- Apollo and Artemis
- Dahj and Soji Asha
- Azan and Rebi
- Jenny and Megan Delaney
- Gorn octuplets
List of half-siblings
- List of half-siblings:
- Aphrodite, Apollo, Artemis, Athena, Hermes, and Hephaestus
- Benjamin Sisko, half-brother of Judith Sisko and her two brothers
- Jake Sisko, half-brother of Benjamin Sisko's unborn (as of 2375) child
- Spock and Sybok, half-brothers
- Tora Ziyal
- Ian Troi, half-brother of Thaddeus and Kestra Troi-Riker
- Kestra and Deanna Troi, half-sisters of Lwaxana Troi's unborn (as of 2372) son
List of fictional siblings
- List of fictional siblings:
- Blaine and Jack (VOY: "Future's End")
- Beatrice Burleigh and Henry Burleigh (VOY: "Cathexis", "Learning Curve", "Persistence of Vision")
- Piotr Chekov, the fictional brother of the very real Pavel Chekov (TOS: "Day of the Dove")
- Dara and her brother (TNG: "Hero Worship")
- One of Three, Two of Three, and their unnamed sibling (VOY: "Author, Author")
- Tweedledum and Tweedledee (TOS: "Plato's Stepchildren")
- The Twin Mistresses of Evil (VOY: "Thirty Days")
- The Unnamed fictional brother of the very real Jonathan Archer (ENT: "North Star")