cast a shadow / cloud over / on sth

/kˈast ɐ ʃˈadəʊ klˈaʊd ˌəʊvəɹ ˌɒn ˌɛstˌiːˈeɪtʃ/

/kˈæst ɐ ʃˈædoʊ klˈaʊd ˌoʊvɚɹ ˌɑːn ˌɛstˌiːˈeɪtʃ/

[phrase]

to cast a shadow / cloud over / on sth

[PHRASE]

to cause a situation to become less hopeful or enjoyable

Examples

1. My brother's heartbreak is casting a cloud over my wedding.

2. Imprisonment of student casts a shadow on Human Rights Council candidacy.

3. Personal failures, disconnect from friends, and academic disappointments casted a cloud on my sense of purpose.

4. A solar eclipse is when the Moon blocks the Sun, casting a shadow on the Earth, and a lunar eclipse is when the Earth blocks the Sun, casting a shadow on the Moon.