The most common and most likely answer to this crossword clue is the 12 letter word ASYMMETRICAL
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More clues leading to the result ASYMMETRICAL
Buddy explains!

The straight part
We know that "lacking a logical design" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case lacking a logical design = asymmetrical.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 ASYMMETRICAL mean?
ASYMMETRICAL adjective- Not symmetrical.
- (of a question) Presenting a false dilemma, or a choice between two things which are not opposites.