The most common and most likely answer to this crossword clue is the 7 letter word GUMSHOE
I've seen this crossword clue in The Times
G
U
M
S
H
O
E
More clues leading to the result GUMSHOE
- Maybe Sam Spade sticks with another tool for gardener
- Idiot turned up with what may be Oxford detective
- Detective showing face around Oxford?
- Detailed mugshot snapped by Eastern US cop
- Rubber sole under this dental hygienist’s instrument, maybe
- American detective in Oxford possibly having something to chew on
Buddy explains!

The straight part
We know that "Maybe Sam Spade" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case maybe sam spade = gumshoe.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 GUMSHOE mean?
GUMSHOE noun- A sneaker or rubber overshoe.
- A detective.
- To act as a detective.