1.
If you say that someone or something has come out of left field or is out in left field , you mean that they are untypical, unusual, or strange in some way.
The question came out of left field, but Mary Ann wasn’t really surprised...
He is, like most theorists, out there in left field, ignoring the experimental evidence.
N-SING : usu prep N
2.
Left-field means slightly odd or unusual. ( mainly BRIT INFORMAL )
...a left-field cabaret act...
Her parents were creative and left-field and wanted Polly to become a singer or a truck driver.
= unconventional
ADJ : usu ADJ n