How to obtain "diligence" from crossword clue "horse-drawn vehicle industry"

Wiktionary says:

diligence (plural diligences)

1. conscientiousness or determination or perseverance when doing something
2. (religion) One of the seven contrary virtues, opposite the vice of sloth.
3. A public stage-coach. (19th century, now used only in reference to France or other European countries including Great Britain.)

industry (in the sense of "busily working") would match definition 1, and definition 3 is a horse-drawn vehicle, if an obscure one. I had no idea!

Here's the etymology of the third meaning given at the Wiktionary.

From the secondary French sense comes the old usage of diligence for "public stage coach" (1742; dilly for short), from a French shortening of carrosse de diligence.

O.Fr. diligence means "attention, care; haste, speed," so carrosse de diligence means "speedy coach."

The Encylopaedia Britannica expands on how the diligence differs from the american stagecoach.