To understand this question, the user needs to know the meaning of the phrase "star-crossed lovers." This phrase refers to lovers who are destined to be together but are prevented by circumstances beyond their control.

Now, let's go through each option and explain why it is right or wrong:

A. Star-crossed means unlucky, i.e. not favoured by the stars - This option is correct. The phrase "star-crossed" comes from the belief in astrology that the positions of the stars and planets at the time of a person's birth can influence their fate. "Star-crossed lovers" are therefore unlucky in love because the stars are not aligned in their favor.

B. Lovers who are blinded by their love for each other - This option is incorrect. While "star-crossed lovers" are often deeply in love, the phrase specifically refers to lovers who are prevented from being together, rather than those who are blinded by their love.

C. Lovers who foolishly believe in idealistic love - This option is incorrect. "Star-crossed lovers" are not necessarily foolish or naive; rather, their love is thwarted by external circumstances beyond their control.

D. Lovers who try to imitate their idols - This option is incorrect. "Star-crossed lovers" are not defined by their attempts to imitate others, but by their own circumstances and the barriers that keep them apart.

Therefore, the answer is: A. Star-crossed means unlucky, i.e. not favoured by the stars.