The most common and most likely answer to this crossword clue is the 7 letter word HEARKEN
I've seen this crossword clue in Independent
H
E
A
R
K
E
N
More clues leading to the result HEARKEN
Buddy explains!

The straight part
We know that "Old attend to" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case old attend to = hearken.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 HEARKEN mean?
HEARKEN verb- (obsolete except poetic) To hear (something) with attention; to have regard to (something).
- To listen; to attend or give heed to what is uttered; to hear with attention, compliance, or obedience.
- To enquire; to seek information.