The most common and most likely answer to this crossword clue is the 6 letter word REMARK
I've seen this crossword clue in Independent
R
E
M
A
R
K
More clues leading to the result REMARK
- Something said about old German currency
- Correct homework again, and make comment
- English maiden aboard river boat, say
- Comment about teacher’s assessment
- Comment about competitor's starting place
- Observe scripture lesson — and what is being studied?
- Kramer’s taken aback, giving notice
- Observation on gospel
- Comment on old currency
- Gospeller supporting religious teachings, it’s said
Buddy explains!

The straight part
We know that "Observe" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case observe = remark.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 REMARK mean?
REMARK noun- An act of pointing out or noticing; notice or observation.
- An expression, in speech or writing, of something remarked or noticed; a mention of something
- A casual observation, comment, or statement
- To make a remark or remarks; to comment.
- To express in words or writing; to state; to make a comment
- To pay heed to; notice; to take notice of
- To mark in a notable manner; to distinguish clearly; to make noticeable or conspicuous; to point out.
- (engraving) A small design etched on the margin of a plate and supposed to be removed after the earliest proofs have been taken.
- (engraving) Any feature distinguishing a particular stage of the plate.
- (engraving) A print or proof distinguished by such a mark.
- A mark that replaces another mark.
- To mark again.