The opposite of noble using a prefix would be ignoble.
The opposite of judge using a prefix is misjudge.
The opposite of merciful using a prefix is merciless.
The opposite of "pronounce" using a prefix would be "mispronounce."
The opposite of active using a prefix is "inactive."
Disobedience
Impious
unpleasant
Disobedience
The opposite of merciful using a prefix is merciless.
The opposite of sever is conjoin.
Anti-social.
the prefix for noble is 'ig' ie. ignoble
The prefix 'dis-' is used in this sense as 'to do the opposite of', as in 'disallow'. To disconnect, therefore, is to act in the directly opposite of 'connect'.
there's no prefix for noble
You may be going for the word expatriate.
Construct
Hypo is the opposite of the prefix hyper.