Sanctimonious and sanctity are easily confused words.
The spell-check application of most word processing software programs would not catch a slip-up of these two words. Spell-check is looking for words that aren’t in its dictionary, and words that resemble words in its dictionary, but are possibly spelled wrong. Spell-check isn’t perfect. It doesn’t know and can’t guess what word you wanted, or what word you meant, it can only judge the words on the page. If you used words that are all spelled correctly, it gives you a pass anyway.
Autocorrect suggests words that start with the same letters. It’s suggesting what word you may want to save time, but quite often, its suggestions are pretty off base. They don’t help you out, but they do make you laugh.
Sanctimonious (pronounced “saynk-tih-moh-knee-uhs”) is an adjective with negative connotations. It describes someone who puts on a show of religious integrity, piety, or “holier than thou” attitude towards others.
Sanctity (pronounced “saynk-tih-tee”) is a noun. It means something sacred or holy.
The following story uses both words correctly:
Sancho was married for 20 years and espoused the sanctity of matrimony. He counseled others on their relationship struggles. He was controversial by confronting and calling out people who got divorced during his presentations.
So it surprised everyone many years later when it was revealed he had five children with two other women. In hindsight, his advice was viewed as sanctimonious, not to mention hypocritical.