a fully differentiated structural and functional unit in an animal that is specialized for some particular function
This is the classical definition of an organ.
an organ is a group of different tissues working together to make an organ for example a ears lungs, heart
An organ for aerial respiration; -- commonly in the plural.
The heart can be defined as the organ that pumps blood.
The fleshy, movable, muscular organ, attached in most vertebrates to the floor of the mouth, that is the principal organ of taste.
A collection of tissue that carry out a specialized function of the body.
Tissue is a group of organ joined together.
A disease is when you have a body malfunction or an organ is not working right.
Colon.
A gland is a cell, group of cells, or organ producing a secretion.
This is the classical definition of an organ.
The definition of the word liver is "a large lobed glandular organ in the abdomen of vertebrates, involved in many metabolic processes."