I’ve seen too many examples of intact written as two words to go on assuming that they are typographical errors.
Photo caption: A couch that was left in tact after the terrorist attacks on the World Trade Center.
Question on medical forum: Is chest muscle left in tact after MastX?
Question on aviation site: Why are there only 2 Stukas left in tact today?
The adjective intact is written as one word. It means “whole, entire, not affected by anything that injures. ” Ex. An animal that has not been spayed or neutered is said to be “intact.”
The literal meaning of intact is “untouched.” The “in” prefix means “not.” The “tact” comes from a verb meaning “to touch.”
The noun tact has the same origin. An obsolete use is “sense of touch.” Now the word’s main use is figurative:
tact – ready and delicate sense of what is fitting and proper in dealing with others, so as to avoid giving offence, or win good will; skill or judgement in dealing with men or negotiating difficult or delicate situations; the faculty of saying or doing the right thing at the right time. (OED)
As for intact, let’s keep it, well, intact.