Here is an online etymology definition for the word, "Saint":
saint (n.)
early 12c., from Old French saint, seinte "a saint; a holy relic," displacing or altering Old English sanct, both from Latin sanctus "holy, consecrated" (used as a noun in Late Latin; also source of Spanish santo, santa, Italian san, etc.), properly past participle of sancire "consecrate" (see
sacred). Adopted into most Germanic languages (Old Frisian sankt, Dutch sint, German Sanct).
So yes, it means "holy' - yet it is those who are most mature in the Lord (fully surrendered to God), I think, who are the most holy. But even those not yet fully surrendered seem to be called by the terms of "saints" in the Bible. I don't have assurance that anyone who is less than fully surrendered to God, is yet secure in their salvation. BUt some of of them go on to full spiritual maturity, and others do not. Naturally, those who do not in this life won't end up in heaven. Paul expressed his concern that believers under him in Galatia, would go on to full maturity.
Gal 4:19-20
19 My little children, of whom I travail in birth again until Christ be formed in you,
20 I desire to be present with you now, and to change my voice; for I stand in doubt of you.
KJV
There are also some who profess to be CHristians but who have no softness of heart or sincerity at all, I know, judging by the Sower parable.
Mark 4:14-15
14 The sower soweth the word.
15 And these are they by the way side, where the word is sown; but when they have heard, Satan cometh immediately, and taketh away the word that was sown in their hearts.
KJV