1. most containing or resembling starch; most stiff or rigid in texture
Usage: superlative form of starchy
2. most formal, stiff, or pompous in manner or behavior
Usage: superlative form of starchy; informal

Examples

• This is the starchiest shirt I own.
• The potatoes were the starchiest vegetables on the plate.
• He gave the starchiest speech of the evening.
• Her grandmother was the starchiest person in the family.
• The starchiest collar made his neck uncomfortable.
• Among all the professors, he had the starchiest demeanor.