No, “illegitimate” is not a term we use in Catholicism.
No, illegitimate
is a term we use in Catholicism: specifically, in canon law, since many things may be tied to one’s status as legitimate or illegitimate (for example, inheritor rights, or succession rights: for example, for royalty). Granted, it matters much less now than it once did, but it’s still sometimes important. And no, jayk15, you’re not illegitimate.
Your parents’ marriage was a putative marriage, so long as one or both parties had a good-faith belief that it was a valid marriage, and it seemed to be a valid marriage externally. Here’s how the Catholic encyclopedia defines it:
Putative (Latin, *putativus *supposed) signifies that which is commonly thought, reputed, or believed. A putative marriage, consequently, in canon law is a matrimonial alliance which is commonly reputed to be valid, and is sincerely believed by one at least of the contracting parties to be so in the eyes of the Church, because entered into in good faith; but which in reality is null and void, owing to the existence of a diriment impediment. The Church too in her external forum recognizes such a marriage, until its invalidity be proved; and concedes to the children born thereof the rights of legitimacy.
newadvent.org/cathen/12584a.htm
Under Catholic canon law, “children conceived in, or born from, a valid or putative marriage are legitimate” (canon 1137). Canon 1138 sets up a time limit for this (not less than 180 days after the celebration of ‘marriage,’ and not more than 300 days after the ceasing of “the conjugal life,” if the couple separates).
Finally, if the marriage is annulled, it was *never *a marriage in the eyes of God. It doesn’t go from being a “'til death do us part” legitimate marriage to an illegitimate marriage. Rather, it was **never **a marriage in the sense that God uses the term.
So short answer: if your parents believed in good-faith that they were married, and outsiders believed so as well, you’re legitimate, even if the marriage wasn’t.