Both the initial and final consonants are retroflex d sounds ɖɪːɖ. They could both be written 'rd' and in fact you may sometimes see this word spelt rdird but dird is also acceptable. Listen to the audio:
http://words.bininjgunwok.org.au/words/dird

Other related words are:

1. dirdko 'moonlight, shadow of moon'
2. dirdkan 'hunt by moonlight'
3. dird naladjarr 'half moon (on wax)'.
4. Dird nayuyhmi (or bukkulurl) 'full moon'

Dird boken ka-ni.
He's staying for two months.

Dird lirrk ba-kurrmeng. (Kundjeyhmi)
The moon's first crescent has appeared (a new moon).

Dird nayuyhmi, namarnde kabarri-woyiknarren.
The moon is full, and spirit beings can see their own shadow.

Kun-ngol mimbalhmeng dird.
The clouds have blocked the moon.