Possible Clues:

• Tranquil
• At peace
• What Keats called Death to make us feel a difference
• Affording rest
• Relaxing
• Tranquil fellow in rough sea, not initially blue
• Giving relief
• Cease fulminating, though not entirely tranquil
• Sounds as if e's not able to take any more with comfort
• Hear Cockney is replete? That was painless