triphthong /trifˈthong, tripˈ/

1. A combination of three vowel sounds in one syllable (phonetics)
2. (loosely) a trigraph

triphthongal /-thongˈgl/ adjective

• cotton waste
• cottonweed
• cottonweeds
• cottonwood
• cottonwoods
• cotton wool
• cotton wools
• cotton-worm
• cotton-worms
• cottony
• cottony-cushion scale
• cottown
• cottowns
• cotts
• cottus
• cottuses
• cotwal
• cotwals
• cotylae
• cotyle
• cotyledon
• cotyledonary
• cotyledonous
• cotyledons
• cotyles