Condescends to have signed (6)
I believe the answer is:
deigns
'condescends' is the definition.
('deign' can be a synonym of 'condescend')
'have signed' is the wordplay.
'signed' anagrams to 'DEIGNS'.
However, I am unsure how the anagram is indicated.
'to' acts as a link.
Can you help me to learn more?
(Other definitions for deigns that I've seen before include "Stoops, condescends" , "Does something beneath one's dignity" , "Condescends, is loftily gracious" , "Condescends by design" , "Condescends to or patronises" .)