Here at O.19.177, the epithet of the Dorians is trikhā́īkes (Δωριέες ... τριχάϊκες), which reflects the traditional division of Dorian communities into three phūlai ‘subdivisions’, Dumânes/Hulleîs/Pámphūloi. So, I interpret the formation *trikhā-u̯īk- to mean ‘with three-way homes’, where *u̯īk- is the same root that we find in oikos ‘home’, from *u̯oikos.