老大

lǎodà
  1. old age
  2. very
  3. eldest child in a family
  4. leader of a group
  5. boss
  6. captain of a boat
  7. leader of a criminal gang

CEDICT

Entry Composition

1 老 lǎo
  1. prefix used before the surname of a person or a numeral indicating the order of birth of the children in a family or to indicate affection or familiarity
  2. old (of people)
  3. venerable (person)
  4. experienced
  5. of long standing
  6. always
  7. all the time
  8. of the past
  9. very
  10. outdated
  11. (of meat etc) tough
2 大 dà
  1. big; large; great
  2. older (than another person)
  3. eldest (as in 大姐 dàjiě)
  4. greatly; freely; fully
  5. (dialect) father
  6. (dialect) uncle (father's brother)