The most common and most likely answer to this crossword clue is the 6 plus 6 letter word SECOND STRING
I've seen this crossword clue in The Daily Telegraph
S
E
C
O
N
D
S
T
R
I
N
G
More clues leading to the result SECOND STRING
- Reserves with which to back horses, perhaps
- … as these may do in next series
- Alternative choice in back row
- Back with cord used in alternative plan
- Reserve supports Hertfordshire town
- Reserves extra food with group consuming tons
- After short time get train as an alternative
- Moments before time, call backups
Buddy explains!
The straight part
We know that "alternative plan" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case alternative plan = second string.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does SECOND STRING mean?
SECOND STRING adjective- Belonging to the second string of a team
- Substitute or replacement
- Second most important