嫡子

dízǐ
son, esp. the eldest son, of the wife (contrasted with 庶子 shùzǐ)

CEDICT

  1. (chiefly historical) son of one's legal wife (as opposed to a concubine)
  2. (specifically) eldest son of one's legal wife (as opposed to one's concubine)
  3. eldest son of one's legal wife (as opposed to one's concubine)
  4. son of one's legal wife (as opposed to a concubine)

Wiktionary

  1. 正室所生的長子。
  2. 正室所生的兒子。

重編國語辭典

  1. 正室所生的兒子
  2. 正室所生的長子

維基詞典

Entry Composition

1 嫡 dí (bound form) of or by the wife, as opposed to a concubine (contrasted with 庶 shù)
=2 子 zǐ
  1. son
  2. child
  3. seed
  4. egg
  5. small thing
  6. 1st earthly branch: 11 p.m.–1 a.m., midnight, 11th solar month (7th December to 5th January), year of the rat
  7. viscount, fourth of five orders of nobility 五等爵位 wǔděngjuéwèi
  8. ancient Chinese compass point: 0° (north)
  9. subsidiary; subordinate; (prefix) sub-
=2 子 zi noun suffix, as in 椅子 yǐzi "chair"