温める

あたためる, あっためる, ぬるめる, ぬくめるatatameru

ichidan verb · transitive

1. to warm (up)
2. to heat (up)
3. to sit on (an idea, plan, etc.)
4. to keep to oneself
5. to nurse
6. to mull over
7. to renew (an old friendship)
8. to take for oneself

Study it in Yanamino