"Blend of Teri and Lynn"
The name Terilyn is commonly a female name from the "American" origin.
Terilyn is a twentieth-century American formation that joins Teri, a short form of Teresa or Terri, with Lynn, a given-name element taken from the Welsh word llyn, meaning lake. The combination follows the established pattern of English names built from a first element plus -lyn, and it appears in United States birth records from the 1940s onward.
The pronunciation of Terilyn is TER-ee-lin.