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。As he's just up on his high horse again. to assume a haughty attitude; to behave arrogantly
Also written 踏ん反り返る【ふんぞりかえる】