1. (尤指老式的或有欠缺的)解决方案;未必奏效的计策
You can refer to ideas or theories about how something should be done as nostrums, especially when you think they are old-fashioned or wrong in some way.

2. (未经科学证明有效的)灵丹妙药，神药
If you refer to a medicine as a nostrum, you mean that it is not effective or has not been tested in a proper scientific way.

1. patent medicine whose efficacy is questionable

2. hypothetical remedy for all ills or diseases
once sought by the alchemists

Synonym: panaceacatholiconcure-all