IPA: /ˈʌndərˌbrɛd/
KK: /ʌndərbrɛd/
Describing someone or something that is of mixed breed or not of pure lineage, often implying poor upbringing or lack of refinement.
The horse was considered underbred, lacking the pedigree of its competitors.
Underbred → It is formed from "under-" (meaning beneath or below) and "bred" (from Old English "bredan", meaning to breed or raise). The word "underbred" refers to being of inferior breeding or lower quality in terms of lineage or upbringing.
Think of something that is 'beneath' ('under-') the standard of breeding or upbringing — that's why underbred means of lower quality.
No commonly confused words.