-branch \ˌbraŋk, -ai-\noun combining form (-s) Etymology: New Latin -branchia ones having (such or so many) gills & -branchus one having (such or so many) gills (from Greek branchos gill, irregular from Greek branchia gills) 1.: one having (such or so many) gills < cryptobranch > < dibranch > 2.: gill < arthrobranch > : organ like a gill < actinobranch >