Sure, it is possible, I suppose. Anybody can choose to attach whatever meaning to whatever in their life they wish.
An atheist who enlists in the military during a time of war to serve her/his country, then gets shot on the battlefield and lays there bleeding to death, can take satisfaction in knowing, in the final moments before her/his death, that they did something meaningful for king and country with their life. I don't wish to take that away; such is incredibly noble. (And thank God for those people!!)
The problem, though, is what to make of the seemingly meaningless suffering in the world. Say, a very small Jewish child born during the Holocaust who knew nothing but cruelty and suffering until a young death that seemed to accomplish absolutely nothing whatsoever good in the world. Theistic religion claims to be able to attach meaning to this person's life as well. Their suffering was not in vain because they are to spend eternity in Paradise with God.
This illustrates a little the difference between the eternal vs. temporal "meaning" we're discussing... if that helps clear it up.
Peace