The most common and most likely answer to this crossword clue is the 7 letter word EPOCHAL
I've seen this crossword clue in The Daily Telegraph
E
P
O
C
H
A
L
More clues leading to the result EPOCHAL
- Manage to come up with a sci-fi computer that’s momentous
- Very important office’s opening in new chapel
- English mate guards old church over many years
- English friend goes round old church that is historically significant
- Survive after revolution and note uprising as historically significant
- Historical prince found after robe’s returned
- To get through when recalled by prince is of major importance
- Highly important to survive setback! Stop wasting time
Buddy explains!
The straight part
We know that "historically significant" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case historically significant = epochal.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 EPOCHAL mean?
EPOCHAL adjective- Of or pertaining to an epoch
- Highly important or significant; monumental, epoch-making