The most common and most likely answer to this crossword clue is the 7 letter word INHALED
I've seen this crossword clue in The Guardian
I
N
H
A
L
E
D
Buddy explains!

The straight part
We know that "Took in" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case took in = inhaled.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 INHALED mean?
INHALED verb- To draw air into the lungs, through the nose or mouth by action of the diaphragm.
- To draw air or any form of gas (either in a pure form, or mixed with small particles in form of aerosols/smoke -sometimes stemming from a medicament) into the lungs, through the nose or mouth by action of the diaphragm.
- To eat very quickly.