The opposite of 'big' is little.
Ennead.
Apples
leaving
payback
ahchoobaboonbamboobloodybloomsbottomcohortcooledchoosecottoncowboyfooledfootedgloomygroomedgroovehoodedhoovesloosermaroonnoodleoblongpoodlerebootretoolrobotssaloonschoolscoopssmoothsnoopssoonersoothespookyspoonstattootycoonwoodenwoolendoodle
The opposite of unusual is common.
sooner
mighty
This question in unanswered.
"prompt" is one possibility
A six letter word that has the same meaning of 'rue' is regret.
a six letter word meaning not attractive: SO UGLY!
Sudden
client
parted
Borrow.
little