noun
1.
a chemical substance that is found in very small amounts
2.
a chemical substance that living things, especially plants, need only in very small amounts to be able to grow well
noun
1.
a chemical substance that is found in very small amounts
2.
a chemical substance that living things, especially plants, need only in very small amounts to be able to grow well
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005