二つの文は表現こそ違うが、同義である。
The two sentences are worded differently, but they mean the same thing.
彼にとって仕事を失うことは人生を失うことと同義だった。
For him, losing his job was the same as losing his life.
沈黙は必ずしも同意と同義ではない。
Silence is not necessarily the same as consent.
この文脈では「自由」は「責任」とほぼ同義に使われている。
In this context, "freedom" is used almost synonymously with "responsibility."