弱よわ腰ごし

na-adjective, noun which may take the genitive case particle 'no', noun

weak-kneed; timid; lacking firmness

Describes a person, attitude, or stance that is irresolute, easily yielding, or lacking backbone, especially in negotiations or confrontations.

• 交こう渉しょうで弱よわ腰ごしな態たい度どを見みせてはいけない。

  You must not show a weak-kneed attitude in negotiations.