Increase
The word that has only four letters and is the opposite of mean in NICE
Imprison is a word which has the opposite to liberate and has eight letters
Those letters will spell reduce.
star
Tigers
spend
pull
Polite is a 6-letter word that is the opposite of rude.
Horizontal
Unscrambled, the letters 'cureed' spell the word reduce.
The two letters that mean the opposite of full are "e" and "m", representing the word "em" which means empty.
The word is possibly "muted."