(adjective) literally means 'no spine', to describe someone that stands / sits with poor posture or slouches; metaphorically to describe someone that lacks backbone / spineless; to describe something (such as a plan or a strategy) or someone that is unreliable / undependable 1.
Definitions (粵典–words.hk)
形容詞
冇骨氣、靠唔住 to have no backbone, has no guts; literally: no waist bone
做人冇腰骨,又點可以做大事呀?
做人冇腰骨,又点可以做大事呀?
zou6 jan4 mou5 jiu1 gwat1, jau6 dim2 ho2 ji5 zou6 daai6 si6 aa3? Without bravery, how can one achieve high?