The opposite of unusual is common.
Profit
A six letter word that starts with U is upward.
MIRROR is a six letter word with three r's in it
A six letter word for undeliverable mail is nixies.
The six-letter word is closed.
Sudden
little
reward
export
The opposite of unusual is common.
sooner
mighty
This question in unanswered.
Profit
"prompt" is one possibility
ADJECTIVE : The opposite of giant would be "little" (or possibly minute). NOUN : The opposite of a giant would be a "midget" (or possibly a shrimp).