The most common and most likely answer to this crossword clue is the 7 letter word EARWORM
I've seen this crossword clue in The Times
E
A
R
W
O
R
M
More clues leading to the result EARWORM
- Unforgettable air of war Rome aroused
- Repetitive strain injury for mare holding column up
- A memorable lay one can’t get out of head?
- Repetitive strain injury of Mr A Rowe
- More war-wounded, number hard to forget?
- European member admits line cocked up in memorable song
- Catchy tune more raw in composition
- It’s hard to forget war Rome lost
- Catchy song framework: cut the beginning and end, then remix
Buddy explains!

The straight part
We know that "Repetitive strain" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case repetitive strain = earworm.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 EARWORM mean?
EARWORM noun- A tune that keeps replaying in one's head or that one keeps thinking about, especially if unwanted.
- (originally United States) Short for corn earworm (“larva of the moths Helicoverpa zea (syn. Heliothis zea) and Helicoverpa armigera, which are agricultural pests”).
- An earwig.