Tentative
Temporary
noun, prefix, の adjective
Temporarily determine something. That makes it tentative and temporary.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
こちらの料金設定は暫定的ですのでご留意下さいませ。
Please bear in mind that these prices are temporary.