The most common and most likely answer to this crossword clue is the 5 plus 3 plus 3 plus 4 letter word EVERY NOW AND THEN
I've seen this crossword clue in Financial Times
E
V
E
R
Y
N
O
W
A
N
D
T
H
E
N
More clues leading to the result EVERY NOW AND THEN
- Occasionally have on trendy new pants
- New oven Henry wanted periodically
- Always handy, went on working periodically
- Just on occasion or literally all the time?
- English extremely negative – stick therefore follows, from time to time
- The renowned navy is at sea
- The renowned Navy messed up occasionally
- The navy renowned at sea? Not all of the time
- The navy renowned at sea on occasions
- Why a tendon never ruptured — or only occasionally
Buddy explains!
The straight part
We know that "at regular intervals/ (5,3,3,4)" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case at regular intervals/ (5,3,3,4) = every now and then.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.