This is a very obscure word.
Sulinday is a small hat that can be transformed into an air vessel. It is featured in a song story about the heroine Matabagka, sister of the chief Bukidnon hero Agyo.
It has also been referred to as a sadok.
KAHULUGAN SA TAGALOG
sulinday: isang tila salakot na panabing sa ulo na maaaring gawing sasakyan sa hangin
