You: "I know how the Church condemns abortion--I was just wondering whether or not it is clearly held to be an infallible teaching."
Me (earlier): "Yes, it is to be held by all the faithful."
Sorry: I was not quite clear. "it is to be held by all the faithful" is Catholic-high-falutin-talk for "infallible." You will usually see the longer phrase in an official document, like "Ordinatio Sacerdotalis" (JPII) or "Munificentissimus Deus" (Pius XII) where neither Pope, if I remember correctly, uses the word "infallible," but proclaims "infallibly."