irreproachable
Concise Oxford English Dictionary © 2008 Oxford University Press:
irreproachable/ɪrɪˈprəʊtʃəbl/
▶adjective beyond criticism.
– derivatives
irreproachability noun,
irreproachably adverb.
irreproachability noun,
irreproachably adverb.
'irreproachable' also found in these Oxford entries:

