She's such a blabber mouth, she can't keep a secret.
blabber on
Frequency:
60
%
He tends to blabber on about his achievements.
blabber away
Frequency:
50
%
She blabbered away on the phone for hours.
blabber nonsense
Frequency:
45
%
Stop blabbering nonsense and focus on the task at hand.
Idiomatic Expressions for blabber
Phrase: blabber on
Meaning: to talk continuously and often without making much sense
Usage: He just kept blabbering on about his vacation, I couldn't get a word in edgewise.