First and Introductory

First

First adjective - Preceding all others in time or space or degree.
Usage example: her first baby

Introductory is a synonym for first in earliest topic. In some cases you can use "Introductory" instead an adjective "First", when it comes to topics like initial, earliest in order.

Nearby Word: firstly

Introductory

Introductory adjective - Serving as a base or starting point.
Usage example: an introductory art course

First is a synonym for introductory in initial topic. You can use "First" instead an adjective "Introductory", if it concerns topics such as preliminary, opening.

Nearby Word: introduction
Cite this Source
Introductory and First. (2016). Retrieved 2026, August 14, from https://thesaurus.plus/related/first/introductory
First & Introductory. N.p., 2016. Web. 14 Aug. 2026. <https://thesaurus.plus/related/first/introductory>.
Introductory or First. 2016. Accessed August 14, 2026. https://thesaurus.plus/related/first/introductory.
Google Ngram Viewer shows how "first" and "introductory" have occurred on timeline