Adamant, Balky, Bullheaded, Cantankerous, Firm
Author: simileguru
as sturdy as an oak
Athletic, Built to last, Bulky, Determined, Firm
as sure as death and taxes
Abiding, Assured, Changeless, Clear, Confident
as tall as a giraffe
Alpine, Altitudinous, Beanstalk, Big, Great
as thin as a rake
Attenuate, Attenuated, Beanpole, Skinny
as timid as a rabbit
Afraid, Ambivalent, Apprehensive, Shy
as tough as old boots
Brawny, Cohesive, Dense, Durable, Hard
as wise as Solomon
Clever, Careful, Astute
as busy as a bee
Active, Efficient, hardworking, brisk
as steady as a rock
Stable, Fixed, Abiding, Brick-wall, Changeless
as sour as vinegar
Bad-tasting, Gone bad, Unpleasant
as sound as a bell
Alive and Kicking, Effectual, Entire, Firm
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