ulterior
/ʌlˈtɪərɪə(r)/adjective
1- existing beyond what is obvious or admitted; intentionally hidden隐秘不明的; 有意隐瞒的; 别有用心的：
could there be an ulterior motive behind his request?
他的请求是否别有用心？
1.1
- beyond what is immediate or present; coming in the future日后的, 将来的：
ulterior pay promised to the mariners.
许诺给海员的日后报酬。
词源
mid 17th cent.: from Latin, literally 'further, more distant'.