The details are undecided.
Please put the pending documents in the red tray on Koichi's desk.
Her court case has been pending for nearly 13 years. It’s so unfair to have to wait that long.
Something that is not yet decided... it is pending... it is unsettled.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.