The most common and most likely answer to this crossword clue is the 7 letter word BREATHS
I've seen this crossword clue in The Daily Telegraph
B
R
E
A
T
H
S
Buddy explains!
The straight part
We know that "These should indicate life" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case these should indicate life = breaths.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 BREATHS mean?
BREATHS noun- The act or process of breathing.
- A single act of breathing in or out; a breathing of air.
- Air expelled from the lungs.
- A rest or pause.
- A small amount of something, such as wind, or common sense.
- Fragrance; exhalation; odor; perfume.
- Gentle exercise, causing a quicker respiration.