Dictionary

To put a label (a ticket or sign) on (something).

Example: The shop assistant labeled all the products in the shop.

(ditransitive) To give a label to (someone or something) in order to categorise that person or thing.

Example: He's been unfairly labeled as a cheat, although he's only ever cheated once.

To replace specific atoms by their isotope in order to track the presence or movement of this isotope through a reaction, metabolic pathway or cell.

To add a detectable substance, either transiently or permanently, to a biological substance in order to track the presence of the label-substance combination either in situ or in vitro

Having a label, tagged.

Example: The butterfly collection had each specimen labeled with the scientific name on a little piece of paper.

Defined or described.

Example: He was labeled as a racist for his otherwise innocent remark.

Having an atom replaced by a radioactive isotope

Example: Insulin labeled with iodine-125 was used as a tracer