The most common and most likely answer to this crossword clue is the 4 letter word LESS
I've seen this crossword clue in The Guardian
L
E
S
S
More clues leading to the result LESS
- The French succeeded not so much
- Not as much or more, as they say
- Unladen long-range spaceships taking off
- Part of course that’s not supported by bar
- Not so much praise without bishop
- Not as much on, having quit class
- The Parisian, extremely supercilious? To a smaller extent
- Wanting to lay hands on missing book
- A smaller amount belonging to Paul or Dennis?
- In a word, ultimate indication of something lacking? Not so
Buddy explains!

The straight part
We know that "taking off" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case taking off = less.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 LESS mean?
LESS noun- A smaller amount or quantity.
- To make less; to lessen.
- To a smaller extent or degree.
- Minus; not including
- Unless