He 'dedicated' [='devoted'] his life/time 'to' helping the poor. = He 'dedicated himself to' helping the poor. [=he used his time, energy, etc., to help the poor]
We have a 'dedicated' phone line for our computer. [=a phone line that we use only for our computer]
They are a group of highly 'dedicated' [='committed', 'enthusiastic'] individuals.
(..) I am no one special, just a common man with common thoughts. I've led a common life. There are no monuments dedicated to me. And my name will soon be forgotten. But in one respect, I've succeeded as gloriously as anyone who ever lived. (..)2004 The Notebook