Distinguishing Relativism from Contextual Truth

Questions about whether the fact that the truth about one’s age changes over time is an argument for relativism, and how to ground virtues like courage in objective reality without relying on circular definitions.  

• I’ve heard truth doesn’t change and doesn’t contradict itself, but how does yearly change fit into that—e.g., I’m 38 one year and 39 the next. Does this create an argument for relativism?
• If “cowardice” is defined as failing to do what’s right, then calling it “wrong” is just a tautology. How do we ground virtues like courage in objective reality without relying on circular definitions?