This is the 137th most frequent French word.
ma
"Ma" means "my" (possessive adjective, feminine singular).
In this sentence, 'ma' is a possessive adjective used to indicate ownership of the noun 'maison' (house), which is feminine singular.
Ma maison est grande et lumineuse.
My house is big and bright.
In this example, 'ma' functions as a possessive adjective indicating that the feminine singular noun 'voiture' (car) belongs to the speaker.
Ma voiture est garée devant chez moi.
My car is parked in front of my place.
Here, 'ma' is again a possessive adjective, used with the feminine singular noun 'sœur' (sister) to express 'my sister'.