the sound that people often make when they pause in the middle of what they are saying or pause before they speak, often because they are deciding what to say（表示犹豫、沉吟或思考）哦，嗯

US abbreviation foremergency room 急诊室，急救室（emergency room的缩写）

abbreviation for Elizabeth Regina: Queen Elizabeth II伊丽莎白女王（Elizabeth Regina的缩写，指英国女王伊丽莎白二世）

also -or added to some verbs to form nouns that refer to people or things that do that particular activity（加在某些动词后构成名词）做…的人；用于…的物

added to the names of particular subjects to form nouns that refer to people who have knowledge about or are studying that subject（加在特定学科名称后，表示通晓或研究该学科的人）…家

added to the names of particular places to form nouns referring to people who come from those places（加在特定的地名后构成名词）来自（或住在）…地方的人

added to nouns or adjectives to form nouns referring to people who are connected or involved with that particular thing（加在名词或形容词后构成名词）与…相关的人

added to nouns to form nouns or adjectives referring to people or things that have those particular characteristics（加在名词后构成名词或形容词）有…特征的人（或物）