This is the 120th most frequent Greek word.
μια
"Μια" means "a" or "one" (feminine) in English.
In this sentence, 'μια' is used as the indefinite article meaning 'one' or 'a' when referring to a singular, unspecified day.
Μια μέρα θα πάμε να δούμε τη θάλασσα.
One day we will go to see the sea.
Here, 'μια' serves as the indefinite article meaning 'a' when introducing an unspecified singular noun, a cat.
Έχει μια γάτα που είναι πολύ χαριτωμένη.
She has a cat that is very cute.
In this sentence, 'μια' represents the indefinite article 'a,' referring to a single, unspecified question.