DWELL ON / UPON STH


Meaning of DWELL ON / UPON STH in English

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.