Or search: emit, utter, rumble, grumble
1 Syllable: S
bowel, cowl, foul, fowl, growled, Howell, howl, owl, prowl, scowl, souled, towel, vowel
2 Syllables: US
avowal

Found 14 words across 2 groupings. Skipped 8 excess words of a similar stem.