The most common and most likely answer to this crossword clue is the 4 letter word ONCE
O
N
C
E
More clues leading to the result ONCE
- Head, bowled out in past times
- Formerly working with civil engineer
- Formerly working with church
- Got nicked regularly, but no more?
- Individual catching cold in the past
- At a former time, completed cursory examination
- Previously, and never to be repeated?
- Previously held in detention centre
- Individual cops caught in the past
- After playing both sides of cassette
Buddy explains!

The straight part
We know that "Formerly" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case formerly = once.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 ONCE mean?
ONCE adverb- (frequency) One and only one time.
- (temporal location) Formerly; during some period in the past.
- Multiplied by one: indicating that a number is multiplied by one.
- As soon as.
- At a future time.
- As soon as; when; after.