This is the 190th most frequent French word.
mieux
"Better" or "best."
Here, "mieux" is used as part of the phrase "faire de son mieux," which means "to do one's best." This expression indicates effort to the highest ability.
Je ferai de mon mieux pour t'aider.
I will do my best to help you.
In this sentence, "mieux" is used as a comparative adverb to indicate an improved manner in which the action (speaking French) is performed.
Il parle mieux français qu'avant.
He speaks French better than before.
Here, "mieux" functions as part of the construction "il vaut mieux," which translates to "it is better" and is used to suggest a preferable option or action.