What does "trace element" mean?

A chemical element present in a sample in very small quantities.

Trace element

Common synonyms include: essential micronutrient, gallium, manganese, microelement, micronutrient, minor element.

noun

noun ·Rare ·Advanced level

Noun

1
A chemical element present in a sample in very small quantities.
2
an element that occurs at very small quantities in the body but is nonetheless important for many biological processes wordnet
3
A chemical element in an organism’s diet that is required in very small amounts in order to maintain proper biochemical function.

Compound of trace (“very small amount”) + element (“chemical element”).