形容詞 arrant:

1. without qualification; used informally as (often pejorative) intensifiers
   同義詞：complete, consummate, double-dyed, everlasting, gross, perfect, pure, sodding, stark, staring, thoroughgoing, utter, unadulterated

1. Don't trust him; he is an arrant hypocrite.
   別相信他，他是個(gè)徹頭徹尾的偽君子。

ar.rant

adj.（形容詞）
Completely such; thoroughgoing:
完全的；徹底的：
例句：
an arrant fool; the arrant luxury of the ocean liner.
十足的傻瓜；極其豪華的定期遠(yuǎn)洋客輪

來(lái)源：
Variant of errant
errant的變體

【引伸】
ar.rantly
adv.（副詞）