1. to plunge into or place under a
   liquid; dip; sink
2. to involve deeply; absorb

Link to present incidents:
"She didn't go by what she thought the best thing was to do or be told to do something, she would do it from the heart and fully immerse herself into it and she cared, she cared massively."

Prince William talking about his mother in an interview to remember Lady Diana's death nearly 10 years ago.