Seeming dangerous or precarious; giving an uneasy or unreliable impression. Colloquial and often used with emotion.
あの脚立は古くて危なっかしいから使わないで。
Don't use that old stepladder — it looks unsafe.
彼の運転はいつも危なっかしくて助手席に座りたくない。
His driving is always so risky that I don't want to sit in the passenger seat.
資金繰りが危なっかしい会社は投資が難しい。
A company with precarious financing is difficult to invest in.
彼女の説明はどこか危なっかしく聞こえた。
Her explanation sounded somewhat dubious/unsteady.