the entire nation; all citizens as a whole (refers to the whole population rather than individuals)
政府は国民全体の意見を聞くために調査を行った。
The government conducted a survey to hear the views of the entire nation.
その法律は国民全体に影響を与える。
That law affects the entire population.
災害時には国民全体で助け合う必要がある。
In times of disaster, the whole nation needs to help one another.