Part of Speech
According to the Merriam-Webster online dictionary, "suppress" is a transitive verb, which is a word that describes an action done to someone.
Etymology
The Online Etymology Dictionary describes the origin of suppress as the Latin word "subprimere" meaning "pushing beneath or down."
Emotional Meaning
Often, people may "suppress their feelings," which means to not express an emotion. In physical terms, you can also suppress a sneeze or other physical reaction, which means to hold it down or inside.
Political Meaning
In political terms, to "suppress" something has a bit more sinister meaning. Merriam Webster's online dictionary defines the term as the usage of power or authority to end an event or way of thought. It can also mean to prevent the spread of information, ie. suppressing books or publications.
Scientific Meaning
Finally, suppress also has scientific connotations in the field of genetics as mutations, viruses, and other expressions can be suppressed, or inhibited from development.