What are ligands?

Answer 1

Ligands are atoms, ions, or molecules that donate electrons to a central molecule via a coordinate covalent bond. The word "ligand" comes from the Latin for "tie," in the sense of a connection.

Answer 2

molecules, either synthetic or of natural origin, that are able to specifically bind certain proteins. In the case of natural ligands, such as hormones, the proteins they bind are called receptors.
www.biotechshares.com/glossary.htm

are any compounds that bind to a receptor.
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In chemistry, a ligand is an atom, ion or functional group that is bonded to one or more central atoms or ions, usually metals generally through co-ordinate covalent bond. An array of such ligands around a centre is termed a complex.
en.wikipedia.org/wiki/Ligands

Answer 3

In chemistry, a ligand is an atom, ion, or molecule (see also: functional group) that generally donates one or more of its electrons through a coordinate covalent bond to, or shares its electrons through a covalent bond with, one or more central atoms or ions (these ligands act as a Lewis base).