The Collaborative International Dictionary
Outmantle
Outmantle \Out*man"tle\, v. t. To excel in mantling; hence, to excel in splendor, as of dress. [R.]
And with poetic trappings grace thy prose,
Till it outmantle all the pride of verse.
--Cowper.
Wiktionary
outmantle
vb. (context transitive English) To surpass in mantle or in splendour, as of dress.