Meaning of 平目 in Japanese

Definition of 平目

ひらめ(hirame) · ヒラメ(hirame) 【平目 ·鮃 ·比目魚】

(n) flounder (esp. the large-tooth flounders of family Paralichthyidae, but also lefteye flounders of family Bothidae)
bastard halibut; olive flounder (Paralichthys olivaceus)

したびらめ(shitabirame) · シタビラメ(shitabirame) 【舌平目 ·舌鮃】

(n) sole (esp. the tonguefishes of family Cynoglossidae, but also the true soles of family Soleidae)
red tonguesole (Cynoglossus joyneri)

ヒラメきん(hiramekin) · ひらめきん(hiramekin) 【ヒラメ筋 ·平目筋 ·比目魚筋】