Target
Subject
noun, の adjective
The versus phenomenon is what you're going up against. It's your target because you're heading towards this phenomenon you're versusing against.
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.
勤続三十年の従業員は、勤続手当として二週間連続有給休暇の対象となる。
Employees who work for this company for thirty years are subject to two straight weeks off with full pay as a reward for their many years of service to the company.