Cryptic crossword clue
Old Bill turned up at empty school! It hurts to show efficiency? 2,2,6

The most common and most likely answer to this crossword clue is the 2 plus 2 plus 6 letter word BE NO SLOUCH

I've seen this crossword clue in The Guardian
B
E
N
O
S
L
O
U
C
H

Buddy explains!

The straight part
We know that "to show efficiency" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case to show efficiency = be no slouch.
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.

Crossword Answer definitions

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