What does 'to blow one's own trumpet' mean?

Answer 1

The phrase "toot your own horn" means to boast, to praise yourself. This is often considered to be immodest. It can mean to be cocky but when you are going to talk about yourself and you don't want to sound cocky or arrogant, you say , "I don't mean to toot my own horn but,..."

The phrase originated in The Bible in Matthew 6: 1-4 (KJV) Jesus teaches us to seek our reward/ acknowledgement of good works from God rather than mankind, including ourselves.

1 Take heed that ye do not your alms before men, to be seen of them: otherwise ye have no reward of your Father which is in heaven.

2 Therefore when thou doest thine alms, do not sound a Trumpet before thee, as the hypocrites do in the synagogues and in the streets, that they may have glory of men. Verily I say unto you, They have their reward.

3 But when thou doest alms, let not thy left hand know what thy right hand doeth:

4 That thine alms may be in secret: and thy Father which seeth in secret himself shall reward thee openly.

Answer 2

The phrase is "blow your own horn." It is typically used to mean that a person is rather prideful, or is boasting about an accomplishment.
It means to brag or to act in a self-promoting or boastful manner.
someone who boasts about themselves
The phrase "Blowing (or touting) your own horn (or trumpet)" means giving praise to yourself.

Answer 3

It refers to bragging about oneself.