silentmotive
nounUK /ˈsaɪlənt ˈməʊtɪv/
US /ˈsaɪlənt ˈmoʊtɪv/
A silent motive is a secret reason for doing something that you do not tell anyone.
She shared her snack with a silent motive, hoping to make a new friend.
OTHER MEANINGS
2. A reason for an action that is kept quiet on purpose.
His silent motive for helping was to learn a secret.
3. A feeling that quietly pushes someone to act without saying why.
Curiosity was the silent motive behind her many questions.
4. A hidden goal behind a kind act.
The gift came with a silent motive: a wish for a favor later.