Meaning of the word "it is a poor dog that is not worth whistling for" in English

What does "it is a poor dog that is not worth whistling for" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

it is a poor dog that is not worth whistling for

US /ɪt ɪz ə pʊr dɔɡ ðæt ɪz nɑt wɜrθ ˈwɪslɪŋ fɔr/
UK /ɪt ɪz ə pɔː dɒɡ ðæt ɪz nɒt wɜːθ ˈwɪslɪŋ fɔː/
"it is a poor dog that is not worth whistling for" picture

Idiom

something or someone is so insignificant or worthless that it is not even worth the slightest effort or attention

Example:
I wouldn't bother fixing that old radio; it is a poor dog that is not worth whistling for.
He didn't even say thank you, but it is a poor dog that is not worth whistling for.