Collocations for defenceless - adj.

be, feel, lie (esp. BrE)
He was kicked as he lay defenceless on the ground.

leave sb
They were left virtually defenceless against enemy attack.

completely, totally, utterly
She felt utterly defenceless.

almost, practically, virtually

against
They were completely defenceless against enemy attack.

poor defenceless
How could anyone steal from a poor defenceless old lady?