The Austronesian Comparative Dictionary

*kayu kayu strong, tough, inflexible

POC kayu kayu strong, tough, inflexible

OC
Manam kai tree; to be strong, to be stubborn
kai-kai firm; to be strong, to be stubborn
Mbula -keke hard, stiff, rigid (cf. ‘tree’)
Bugotu ka-kai to be firm, steady, faithful, right
West Guadalcanal ka-kai strong
Wayan kai strong, tough, powerful; firm, rigid, stiff; hard wood
kai-kai be hard, firm, rigid; strong, tough, powerful
Fijian kau-kau-a strong, hard; strength, hardness
Tongan kau-kau-a strong, especially physically strong; burly, sturdy or robust