To speak too much or unwisely about something
زیاد یا بدون فکر حرف زدن در مورد چیزی، حرف پراندن
What do you know about working hard? You only have had a part time job for two months and now you are giving me advice on that. Sorry to say that but I think you are shooting your mouth off.
shoot your mouth offinformal to talk about something that you should not talk about or that you know nothing about Don’t go shooting your mouth off.
shoot your mouth off (about something)
ˌshoot your ˈmouth off (about sth) idiom
1. to talk with too much pride about sth
2. to talk about sth that is private or secret
Cambridge Advanced Learner's Dictionary - 4th Edition
shoot your mouth off informal
to talk too much in a loud and uncontrolled way:
It's just like Richard to go shooting his mouth off about other people's affairs.
© Cambridge University Press 2013
shoot your mouth off also shoot off at the mouth informal : to talk foolishly, carelessly, or too much about something
• She tends to shoot her mouth off.
• Try not to shoot your mouth off about this to anyone.