I stopped taking the Oxford Dictionary seriously when they decided that "literally" could literally mean "not literally". Rand al'Thor on Literature Stack Exchange, 15.09.2017; accessed on 03.07.2018)

For non-native speakers of English, a “learner's dictionary” is more useful than a dictionary aimed at native speakers. When you choose a dictionary (whether printed or digital), check that it provides usage notes (e.g. on difference between certain synonyms and near synonyms, e.g. "change", "alter" and "modify"), full sentence examples and examples of prepositions that can be used with the noun or verb you are looking up.

Monolingual Dictionaries (British English)

Also useful:

Monolingual Dictionaries (Other Variations of English)

Other Resources about Dictionaries