Cryptic crossword clue
Did deliberate swindle with blueprint to get diamonds 12

The most common and most likely answer to this crossword clue is the 12 letter word CONTEMPLATED

I've seen this crossword clue in The Daily Telegraph
C
O
N
T
E
M
P
L
A
T
E
D

Buddy explains!

The straight part
We know that "Did deliberate" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case did deliberate = contemplated.
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 CONTEMPLATED mean?

CONTEMPLATED verb
  1. To look at on all sides or in all its aspects; to view or consider with continued attention; to regard with deliberate care; to meditate on; to study, ponder, or consider.
  2. To consider as a possibility.

Latest crossword clues with full explanations