Or search: dispiriting, demoralizing, discouraging, disheartening
3 Syllables: SUU
realising, realizing
4 Syllables: SUUU
analyzing, civilizing, equalizing, fertilizing, generalizing, glorifying, horrifying, mobilizing, moralizing, neutralizing, notifying, paralyzing, specializing, stabilizing, symbolizing, tantalizing, utilizing
5 Syllables: USUUU
demoralizing

Found 20 words across 3 groupings.