Grandparent

A grandparent was a name used to describe one's ancestor, namely the parent of one's parent, where the subject in question would be the grandparent's grandchild. Each previous generation of the initial grandparent was given the qualifier of "great", which was then compounded. 

Worf often spoke of his parent's, Sergio and Helena Rozhenko, to his son Alexander as "your grandparents". 

Female
A female grandparent was generally identified as a grandmother, and informally as grandma or nana. 

On the term used by Vulcans was foremother. T'Mir was T'Pol's second foremother ("great-grandmother") and T'Les' foremother ("grandmother"). 

Janeway wondered if a surfer was her "great, great, great...great grandmother". 

Walter Pierce's grandmother was Betazoid. 

Janeway told Seven of Nine that she might could have cousins or grandparents on Earth after Seven told her she had no emotional response to Earth. 

Male
A male grandparent was generally identified as a grandfather, and informally as grandpa, granddad or even gramps. 

On Vulcan the term used by Vulcans was forefather. Spock, in the guise of a "cousin" Selek, assured Sarek familiarity to the former was simply due to "a family resemblance to our forefathers."

Ira Graves claimed to have been a mentor to Doctor Noonian Soong, suggesting that made him "grandfather" to Soong's android creation, Data. 

Deanna Troi's grandfather was someone she spent time with on Betazed while growing up. She later described him as a man who rarely spoke, noting that talking was for off-worlders and people who didn't know any better. When Troi was young, her grandfather would tell her stories to her telepathically as they sat by the fire. Troi would close her eyes and listen to his mind for hours on end. When Troi got older, the only time she could remember his stories was when she went home to Betazed and sat by the fireplace, adding that at times, when she was alone there, it was almost like she could hear his voice inside her head. 

Riley Frazier had fond memories, while growing up in mid-24th century Texas, of picking bluebonnets with her grandfather, who carried a walking stick. 

When Neelix read a letter to Tuvok from his wife, he also told him that his son Sek became a father of a girl. Neelix then asked Tuvok how he should call him now, grandfather, grandpa, or gramps but Tuvok told him "Commander Tuvok" would be sufficient. 

Culture

 * See also:
 * "Obachan"
 * "Moogie"

List of grandparents

 * Jonathan Archer and Esilia, paternal great-grandparents of Karyn Archer (alternate timeline)
 * Benaren and Martis, maternal grandparents of Linnis Paris (alternate timeline) and maternal great-grandparents of Andrew Kim (alternate timeline)
 * Kamin and Eline, maternal grandparents of Kamie
 * maternal grandfather of Karl Four
 * Keldar and Ishka, paternal grandparents of Nog
 * John Kim and Mary Kim, paternal grandparents of Andrew Kim (alternate timeline)
 * George Kirk and Winona Kirk, paternal grandparents of David Marcus, Peter Kirk, and two more grandsons
 * Tiberius Kirk and, respectively paternal and maternal grandfather of George Samuel and James T. Kirk
 * Alexander Marcus and Wallace, maternal grandparents of David Marcus
 * David McCoy, paternal grandfather of Joanna McCoy
 * McCoy's great-great-granddaddy
 * McCoy's great-great-great-great-grandfather
 * Mogh, paternal grandfather of Alexander Rozhenko and Kurn's children
 * Michael O'Brien, paternal grandfather of Molly and Kirayoshi O'Brien
 * Maurice and Yvette Picard, paternal grandparents of René Picard
 * Owen Paris, paternal grandfather of Miral Paris
 * Owen Paris, paternal grandfather of Linnis Paris (alternate timeline)
 * Tom Paris and Kes, maternal grandparents of Andrew Kim (alternate timeline)
 * Connaught Rossa, paternal grandmother of Jeremiah Rossa
 * Sergey and Helena Rozhenko, adoptive grandparents of Alexander Rozhenko
 * Joseph and Sarah Sisko, paternal grandparents of Jake Sisko
 * Skon, paternal grandfather of Sybok and Spock
 * Solkar:
 * paternal grandfather of Sarek
 * paternal great-grandfather of Sybok and Spock
 * Talur's grandmother, grandmother of Talur
 * Ian Andrew and Lwaxana Troi, maternal grandparents of Ian Andrew Troi, Jr.
 * John Torres and Miral, maternal grandparents of Miral Paris
 * Cyrus
 * paternal grandfather of Charles Tucker II
 * paternal great-grandfather of Charles Tucker III and Elizabeth Tucker
 * Charles Tucker I:
 * paternal grandfather of Charles Tucker III and Elizabeth Tucker
 * paternal great-grandfather of Elizabeth and paternal great-grandfather of Lorian (alternate timeline)
 * Charles Tucker II, paternal grandfather of Elizabeth and paternal grandfather of Lorian (alternate timeline)
 * Tuvok and, paternal grandparents of
 * T'Meni:
 * paternal grandmother of Sek, Asil, and two more grandsons
 * paternal great-grandmother of
 * T'Mir, maternal great-great-grandmother of Elizabeth and maternal great-great-grandmother of Lorian (alternate timeline)
 * Samantha Wildman and Greskrendtregk, maternal grandparents of Sabrina
 * Samantha Wildman and Greskrendtregk, maternal grandparents of Sabrina

List of Vulcan foreparents

 * Skon, forefather of Spock and Sybok
 * Solkar, forefather of Sarek, second forefather of Spock and Sybok
 * T'Meni, foremother of Sek and Asil, second foremother of
 * T'Mir, foremother of T'Les, second foremother of T'Pol, third foremother of Elizabeth and Lorian (alternate timeline)
 * and Tuvok, foreparents of T'Meni
 * and Tuvok, foreparents of T'Meni