The most common and most likely answer to this crossword clue is the 6 letter word WATERY
I've seen this crossword clue in The Guardian
W
A
T
E
R
Y
More clues leading to the result WATERY
- We try a shot that’s far from neat
- Weak women’s sobbing has moved heart
- Half of bitter is, in practice, weak
- Passage about head of Tudor queen is tasteless
- Thin and pale, we try a doctor
- Cautious about alien, upset and weak
- Weak theory oddly incorporated in system
- Suspicious about townie on vacation getting tasteless
- Weak with crying with stomach heaving
- If so, it's not solid — consumed in grimly humorous circumstances
Buddy explains!

The straight part
We know that "Thin and pale" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case thin and pale = watery.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 WATERY mean?
WATERY adjective- Resembling or characteristic of water.
- Wet, soggy or soaked with water.
- Diluted or having too much water.
- (of light) Thin and pale therefore suggestive of water.
- Weak and insipid.
- Discharging water or similar substance as a result of disease etc.
- Tearful.