(archaic)(of an action) be of no help at all to someone
(古)（行動(dòng)）無(wú)助于
not very (or not at all) effective or successful
幾乎（或根本）無(wú)效的
with little (or no) success or benefit
幾乎（或根本）毫無(wú)作用；無(wú)助
he tried to get his work recognized, but to little avail.
他試圖使自己的工作得到認(rèn)可，但卻幾乎毫無(wú)作用。
To make use of.
利用