булбул

булбул: nightingale

Марям булбул барин месарояд.
Mariam sings like a nightingale.
Булбул паррандаи хурдакаки зебо ва хушовоз мебошад.
A nightingale is a small, beautiful and sweet-singing bird.

Bonus:
Here is a proverb. Feel free to discuss the meaning and when you could use this proverb in the comments below.
Шахси беватан – булбули бечаман.
A person without a homeland is like a nightingale without a meadow.
Tajik Wikipedia has a short article about nightingales that is not too difficult to read.