Crossword Puzzle Old TWA hiree

Clue: Old TWA hiree

Oldest musketeer (ATHOS with 5 letters)
Board of directors hirees, for short (CEOS with 4 letters)
Inheritance by next to oldest (SECUNDOGENITURE with 15 letters)
Mark Twain's Dan'l was one (FROG with 4 letters)
'50s oldies syllable (SHA with 3 letters)
What Mark Twain said sounds comforting in the pulpit (ETERNALREST with 11 letters)
12-year-olds (TWEENS with 6 letters)
Gunpowder or Twankay (TEA with 3 letters)
Get older (e.g. AGE with 3 letters)
Kid older than 12 (TEEN with 4 letters)