1. Godan verb with 'ru' ending, Intransitive verb

   to straighten up and stick one's chest out; to throw oneself back (e.g. in a chair); to lean back (arrogantly)

   どうせまたふんぞり返って威張っているだけなのだから。

2. to assume a haughty attitude; to behave arrogantly

Also written 踏ん反り返る【ふんぞりかえる】funzorikaeru