slipping (adj.)

• bad
• cracking
• decadent
• degenerate
• draining
• drooping
• dwindling
• dying
• effete
• fading
• failing
• falling
• flagging
• going
• hopeless
• low
• moribund
• nonviable
• regressive
• retrograde
• retrogressive
• rusty
• sliding
• soft
• stiff
• terminal
• waning
• withering
• worsening