The most common and most likely answer to this crossword clue is the 7 letter word COMBING
I've seen this crossword clue in The Daily Telegraph
C
O
M
B
I
N
G
More clues leading to the result COMBING
Buddy explains!

The straight part
We know that "Searching" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case searching = combing.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 COMBING mean?
COMBING verb- (especially of hair or fur) To groom with a toothed implement; chiefly with a comb.
- To separate choice cotton fibers from worsted cloth fibers.
- To search thoroughly as if raking over an area with a comb.
- To roll over, as the top or crest of a wave; to break with a white foam, as waves.
- The act by which something is combed.
- (in the plural) Individual hairs that drop out when the hair is combed.