1.
to think or talk a lot about sth, especially sth it would be better to forget :
So you made a mistake, but there's no need to dwell on it.
2.
to look at sth for a long time
1.
to think or talk a lot about sth, especially sth it would be better to forget :
So you made a mistake, but there's no need to dwell on it.
2.
to look at sth for a long time
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005