This is the 2042nd most frequent Japanese word.
一生
"One's whole life" or "lifetime."
In this case, "一生" refers to "lifelong" or "continuing through life," emphasizing the enduring significance of the pride he holds.
彼はそれを一生の誇りにしています。
He holds it as a lifelong pride.
In this sentence, "一生" is used to mean "entire life" or "lifespan," emphasizing the act of devoting one's lifetime to an endeavor.
彼は一生を平和のために捧げました。
He dedicated his entire life to peace.
Here, "一生" conveys the concept of "throughout one's life" or "lifelong," highlighting the permanence of the memory of the experience.