### Clue: Love, dropping its first subtle shimmering (6)
### Answer: OBTUSE 
 ### Explanation: O(letter representing 0/"love" in tennis scores) + **anagram of**(… shimmering) [**1st letter of**(… its first) "Love" **deleted from**(dropping …) "subtle"].
Answer: As in an "obtuse-angled triangle", one with an obtuse angle.