Defuse

• to remove the fuse from (an explosive device)
• to reduce the tension or danger in (a difficult situation).

Diffuse:

• to spread over a wide area (or between a large number of people)
• to mix (a gas or liquid) through or into a surrounding substance
• to cause light to spread evenly
• spread out over a wide area; not concentrated or localised
• lacking conciseness or clarity.