Where does “intro” come from?

Intro comes from Latin introductio, the noun form of introductus, the past participle of duco meaning to lead, combined with intra meaning within.

intro (English): An introduction; The opening sequence at...

Definitions

Step	Language	Word	Meaning
1	English	introduction	The act or process of introducing; A means, such...
2	Middle English	introduccioun	—
3	Old French	introduction	—
4	Latin	introductionem	accusative singular of intrōductiō
5	Latin	intrōductiō	—
6	Latin	intrōdūcō	—
7	Latin	intrō	—
8	Latin	intra	within; inside; during; less than
9	Latin	interus	—
10	Proto-Indo-European	h₁énteros	inside, within
11	Proto-Indo-European	-teros	Contrastive or oppositional adjectival suffix

intro — Etymology, Origin & Word History | Etymology Explorer