a plum in your mouth

US /ə plʌm ɪn jʊər maʊθ/
UK /ə plʌm ɪn jʊər maʊθ/
"a plum in your mouth" picture
1.

слива во рту, говорить манерно

an affected way of speaking, as if one has a plum in one's mouth, often associated with upper-class accents

:
He speaks with a plum in his mouth, making him sound very aristocratic.
Он говорит так, будто у него слива во рту, что делает его очень аристократичным.
Her affected accent sounded like she had a plum in her mouth.
Её манерный акцент звучал так, будто у неё слива во рту.