Expectancy is a state of expectation

the state of expecting or hoping that something, especially something good or exciting, will happen

• There was an air of expectancy among the waiting crowd.

  等待的人群心怀期盼。

Expectation is something which is anticipated or is likely to happen.

a belief that something will happen because it is likely

• We are confident in our expectation of a full recovery.

  我们满怀信心地期待着完全康复。