The earliest word I remember that begins with Dalet is דרך. This word is a very good exercise in the distinction of letters. ד dalet, ר resh, and final kaf ך are an early source of confusing shapes for a new learner of the Hebrew written forms. We find this word in Ruth also
Other words in Ruth beginning with ד:
vrvut dabqah bah
Lots of dalet's in the middle of words - but few at the beginning. On to the grammatical ה 'he'.