1. Things or substances that block, hinder, or prevent passage or progress
Usage: Usually plural; can refer to physical barriers or abstract impediments
2. In medicine and phonetics, substances or conditions that obstruct normal function or airflow
Usage: Medical/technical term

1. Serving to obstruct or block; causing obstruction
Usage: Less common than the noun form

Examples

• The fallen trees were major obstructives to traffic flow on the mountain road.
• Bureaucratic obstructives delayed the project by several months.
• The doctor identified several obstructives in the patient's airways.
• Obstructive policies prevented the company from expanding into new markets.
• We had to remove the obstructives blocking the drainage system.
• Political obstructives made it difficult to pass the legislation.