Answer: ruinous

AnswerCrossword Clue
RUINOUS

Druid abandoning dates in France? We will become desperate (7)

RUINOUS

Catastrophic

RUINOUS

Destructive

RUINOUS
Wreaking destruction
RUINOUS
Cataclysmic
RUINOUSBaneful.
RUINOUSDevastating.
RUINOUSDestructive.
RUINOUSDevastating
RUINOUSBringing destruction
RUINOUSLike bankruptcy, maybe