As nouns the difference between stet and stat

is that stet is a symbol used by proofreaders and typesetters to indicate that a word or phrase that was crossed out should still remain. This is usually marked by writing and circling the word stet above or beside the unwanted edit and underscoring the selection with dashes or dots. Alternatively, a circled checkmark may be used in the margin while stat is short for statistic.

As verbs the difference between stet and stat

is that stet is the act of marking previously edited material "stet" to indicate that something previously marked for change should remain as is while stat is to assign statistics to (a monster, etc. in a game).

As an adverb stat is

immediately; now; usually used in medical situations, to connote extreme urgency.