Changed 'alerted' to 'related', perhaps? (7)
I believe the answer is:
altered
'changed' is the definition.
(similar in meaning)
'related perhaps?' is the wordplay.
'perhaps?' indicates an anagram (I've seen 'perhaps' mean this).
'related' with letters rearranged gives 'ALTERED'.
'alerted to' acts as a link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for altered that I've seen before include "Converted" , "Changed, modified" , "Different" , "Reformed" , "Treadle (anag)" .)