adjective. being beyond what is seen or avowed; intentionally kept concealed: ulterior motives. coming at a subsequent time or stage; future; further: ulterior action.

Is Ulteriorly a word?

ul·te·ri·or. adj. 1. Lying beyond what is evident, revealed, or avowed, especially being concealed intentionally so as to deceive: an ulterior motive.

What does it mean ulterior motive?

: a secret reason I think she has an ulterior motive for helping us.