vi.

1. 有用；有益，有幫助[（+against）]
   The medicine did not avail against the disease.

   該藥對此病無效。

vt.

1. 有用於；有益於；有助於
   He availed himself of the opportunity to speak to her.

   他利用這機會和她說話。

n.

1. 效用；利益；幫助[U]
   Speeches and protests were of no avail.

   演講和抗議全都徒勞。

2. 【古】利潤；（尤指賣掉財產後的）所得[P]

v.

1. (avail oneself of) use or take advantage of.
2. help or benefit.

n.