1. Auxiliary

   should (be); bound (to be); expected (to be); must (be)

   Usually written using kana alone

   その飛行機は今ごろは関西空港に当然着いているはずだ。

2. Noun

   nock (of a bow)

3. nock (of an arrow)

4. nock-shaped grip (between thumb and forefinger)

   Sumosee はず押しsee はずおし

5. wooden frame on the tip of the mast of a Japanese ship that prevents the hawser from falling out

Also written 弭【はず】