The most common and most likely answer to this crossword clue is the 4 letter word PEEK
I've seen this crossword clue in Financial Times
P
E
E
K
More clues leading to the result PEEK
- Look to hold back
- Sly look that could be repeatedly said to give top dog annoyance
- Catch sight of wee Kelvin
- Look! Stock up
- Guard, rising, giving sly look
- Take a look at food on way up
- Take a secret look around castle
- Take a brief look at reserve’s back
- Look to get sound from woofer
- Have a quick look and stay back
Buddy explains!

The straight part
We know that "Catch sight of" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case catch sight of = peek.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 PEEK mean?
PEEK verb- To look slyly, or with the eyes half closed, or through a crevice; to peep.
- To be only slightly, partially visible, as if peering out from a hiding place.
- To retrieve (a value) from a memory address.