A kanji used as a prefix meaning help, rescue, or assistance (on-reading 'jo'); mainly appears in compound words.
漢字の「助」は接頭語として、補助や救助の意味を表す（読みは「じょ」）。
The kanji '助' as a prefix expresses assistance or rescue (read as 'jo').
助成金（じょせいきん）は事業を支援するための資金だ。
A subsidy (joseikin) is funding to support a project.
大学では助教（じょきょう）という職位がある。
At universities there is a position called 'jokyō' (assistant professor/lecturer).