The most common and most likely answer to this crossword clue is the 7 letter word NONSTOP
I've seen this crossword clue in The Times
N
O
N
S
T
O
P
More clues leading to the result NONSTOP
- Reflected on points put by, say, Cork Express
- Old Poles in National Trust work continuously
- No bridge partners lead all the time
- Poles wearing no vest without a break
- ...Express: nothing in the news, read no more?
- At first, navvies on street work without a break
- Interminable pontoon game? Briefly succeeded for just one round
- Constant work to support regulars in ongoing way
- On going in opposite directions, best to be persistent
- Partners have agreed over not having a break
Buddy explains!

The straight part
We know that "all the time" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case all the time = nonstop.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 NONSTOP mean?
NONSTOP noun- (travel) A nonstop journey, especially a nonstop flight.
- A convenience store in parts of Europe, open 24 hours a day.
- A linguistic sound that is not a stop; a continuant.
- Without stopping; without interruption or break.
- Describing a point mutation within a stop codon that causes the continued translation of an mRNA strand.
- Without stopping; without interruption or break