This is the 13184th most frequent Russian word.
мила
"Мила" translates to "cute" or "sweet" (often used as a term of endearment).
The word 'Мила' is used here as a proper noun, a given name, denoting a specific individual.
Мила улыбнулась мне, и я почувствовал радость.
Mila smiled at me, and I felt joy.
The word 'мил' (masculine form of 'милый') in this sentence means 'sweet' or 'kind', describing the act.
Её поступок был так мил, что я не мог перестать улыбаться.
Her action was so sweet that I couldn't stop smiling.
Here, 'милая' is an adjective meaning 'cute' or 'charming', describing the noun 'собачка' (little dog).