[in.tro.duc.to.ry] adj (1605): of, relating to, or being a first step that sets something going or in proper perspective "an ~ course in calculus" -- in.tro.duc.to.ri.ly adv
INTRODUCTORY
Meaning of INTRODUCTORY in English
Merriam-Webster English vocab. Английский словарь Merriam Webster. 2012