What does the cryptic crossword clue "Touchdown, in two words, makes you experience sadness (4,4)" mean?

The wordplay uses a charade (building blocks). FEEL (synonym="FEEL") + BLUE (synonym="BLUE") = FEELBLUE The answer is FEELBLUE.

Touchdown, in two words, makes you experience sadness (4,4)

Guardian Cryptic #29226 | 18 Across | 2023-11-13 flower