The most common and most likely answer to this crossword clue is the 6 letter word THOMAS
I've seen this crossword clue in The Guardian
T
H
O
M
A
S
More clues leading to the result THOMAS
- B getting zero in maths debacle
- One writer after 11, another before 27
- This old mum is taking the place of one
- First sign of miracle has to transform doubter
- All the same mass equally? More?
- Seeker of proof getting nothing in maths wrong
- Name Gray had for Welsh poet
- Cook wanted. More might be really useful on the railway
- Theologian at home — pi mask’s blown apart!
- Cromwell, for example, shot a revolutionary when holding mass
Buddy explains!
The straight part
We know that "Seeker of proof" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case seeker of proof = thomas.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.