The most common and most likely answer to this crossword clue is the 8 letter word TRAINEES
I've seen this crossword clue in The Daily Telegraph
T
R
A
I
N
E
E
S
Buddy explains!

The straight part
We know that "Learners" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case learners = trainees.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 TRAINEES mean?
TRAINEES noun- Someone who is still in the process of being formally trained in a workplace.