Or search: befriend, buddy, chum, cobber, crony
1 Syllable: S
2 Syllables: SU
3 Syllables: SUU
3 Syllables: USU
4 Syllables: UUSU
5 Syllables: UUUSU

Found 122 words across 6 groupings. Skipped 73 excess words of a similar stem.