A
LITTLE / SMALL
MINISCULE
For 16 year, we lived in a miniscule flat in the centre of the city.
BIG / LARGE
HUMONGOUS (enorme)
If I were rich, I would buy a humongous house in the country.
GARGANTUAN (gigantesco)
COLOSSAL
ENORMOUS
HIGH
LOFTY
The lofty trees swayed in the wind. (literal use)
He had lofty goals of becoming CEO. (figurative use)
DIFFERENT
CHALK AND CHEESE (idiomatic expression)
My sister and I are chalk and cheese.
DISPARATE (more formal)
We often clash because our political views are so disparate.
SAME
PEAS IN A POD (idiomatic expression)
The brothers were like peas in a pod.
TANTAMOUNT (more formal) - it doesn't mean exactly the same. It means: "virtually the same as"
Calling a Scot an Englishman is tantamount to a declaration of war.