Recognise legend, wacko in peculiar guise (11)
I believe the answer is:
acknowledge
'recognise' is the definition.
(acknowledging is a kind of recognizing)
'legend wacko in peculiar guise' is the wordplay.
'in peculiar guise' indicates an anagram (a peculiar spelling).
'legend'+'wacko'='legendwacko'
'legendwacko' is an anagram of 'ACKNOWLEDGE'.
(Other definitions for acknowledge that I've seen before include "Admit - recognise - thank" , "Indicate obligation to" , "Confirm (receipt)" , "Express thanks for" , "Confess" .)