Meaning and Name Origin
Garreth \g(a)-rre-th\ as a boys' name. Garreth's root is Celtic, and the meaning of the name Garreth is "gentle". Garreth is a derivative of Gareth (Celtic): sir Gareth, noted for his modesty and bravery, was a knight of King Arthur's Round Table. Garreth is also a derivative of Garret: surname derived from Gerald and Gerard, used as a first name and dating from the Middle Ages.
Garreth has 20 more related forms via Gareth, Garret: Garett▼, Garrard, Garretson, Garrett▲, Garritt, Garrot, Garrott, Garry▼, Garth▼, Gary▼, Gaz, Gerrit, Gerritt, Gerrity, Jared▲, Jarod▼, Jarret, Jarrett▼, Jarrot and Jarrott.
Garreth is an unusual first name for males. Garreth is an equivalently uncommon last name too for all people. (2000 U.S. Census)
Below is a graphed comparison of the popularity of the boy name Garreth and corresponding names. Popular alternative forms of Garreth (#unlisted) listed in the Top 1000 are Garett, Garret, Garrett (#236 the previous year), Garry, Garth, Gary (#560), Jared (#296), Jarod, Jarret and Jarrett. These boy names reached the top of their popularity in 1998 and have become significantly less popular since, with versions like Garret, Garth, Gary, Jarod and Jarrett becoming somewhat outmoded. Garrett (#236) and Jared (#296) are two of the more trendy birth names among these, with Garrett going through a rebound in usage. (2014 Birth Statistics)