Absurd, Batty, Bedlamite, Buggy
as obstinate as a mule
stubborn, determined, inflexible, intractable
as old as the hills
Aged, Along in years, Ancient, Broken down
as pale as death
Bloodless, Cadaverous, Colorless, Deathlike, Dim
as plain as day
Apparent, Audible, clear, obvious
as poor as dirt
Bad off, Bankrupt, Beggared, Beggarly
as proud as a peacock
Appreciative, August, Content, Contented
as pure as snow
Authentic, Bright, Classic, Clear, fair
as quick as silver
ASAP, A move on, Abrupt, Accelerated, Active
as safe as a house
Buttoned up, Cherished, Free from danger
as scarce as hen’s teeth
Rare, Scant, Scanty, Seldom
as sick as a parrot
Ailing, Bedridden, Broken Down, Confined
as silent as the grave
Bashful, Buttoned up, Checked, Clammed up
as slippery as an eel
Smooth, Slick, Glassy, Glazed, Greasy
as slow as a snail
Unhurried, lazy, Apathetic, Crawling, Creeping