Ruminative (adjective)

1. Describes someone who is deep in thought and reflective about something.
2. Relating to the habit of chewing food again after swallowing it, as in the process of digestion by ruminants.

Origin:

Derived from the latin word 'ruminare' meaning to chew again.

Examples:

1. He became ruminative after reading the letter from his old friend.
2. After dinner, he would often sit in silence, lost in ruminative thought.
3. Her ruminative nature made her a natural philosopher.
4. The ruminative cow chews its cud for hours, breaking down food into smaller pieces.
5. His ruminative gaze made it clear that he was deep in thought about a problem.