The most common and most likely answer to this crossword clue is the 6 letter word REVERT
I've seen this crossword clue in Independent
R
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More clues leading to the result REVERT
Buddy explains!

The straight part
We know that "go back" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case go back = revert.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 REVERT mean?
REVERT noun- One who, or that which, reverts.
- One who reverts to that religion which he had adhered to before having converted to another
- (due to the belief that all people are born Muslim) A convert to Islam.
- The act of reversion (of e.g. a database transaction or source control repository) to an earlier state.
- (now rare) To turn back, or turn to the contrary; to reverse.
- To throw back; to reflect; to reverberate.
- To cause to return to a former condition.
- (now rare) To return; to come back.
- To return to the possession of.
- To cause (a property or rights) to return to the previous owner.
- To return to a former practice, condition, belief, etc.
- To return to an earlier or primitive type or state; to take on the traits or characters of an ancestral type.
- To change back, as from a soluble to an insoluble state or the reverse.
- To take up again or return to a previous topic.
- (in Muslim usage, due to the belief that all people are born Muslim) To convert to Islam.
- (originally India, now also Singapore, Malaysia, Hong Kong) To reply (to correspondence, for example).
- To treat (a series, such as y = a + bx + cx2 + ..., where one variable y is expressed in powers of a second variable x), so as to find the second variable x expressed in a series arranged in powers of y.