To stand up straighter, often to emphasize one's pride or indignation. In this usage, a reflexive pronoun is used between "draw" and "up."

(通常为使自己显得更重要)挺直腰板，挺胸抬头。在这个用法中draw和up中间通常加一个反身代词。

Like a lot of short men, he tends to draw himself up to his full height in public.

像许多矮个子男人一样，他在公共场合常常是腰板挺得笔直。

The old knight drew himself up straight. " I offer myself in my daughter's place. Release her, and take me as your hostage ".

老骑士挺直腰板：“我愿用自己来交换女儿。放了她，拿我当人质。”