Definition as Noun

• something that serves as a preceding event or introduces what follows
• a minor match preceding the main event

Definition as Adjective

• denoting an action or event preceding or in preparation for something more important

• overture, prelude

• prelim

• "a preliminary investigation"

• "training is a necessary preliminary to employment"; "drinks were the overture to dinner"

• Preliminary vs overture
• Preliminary vs prelude
• Preliminary vs prelim