IPA: //ˈʌltrəʃɔrt//
KK: /ˈʌltrəˌʃɔrt/
Very short in length or duration, often used to describe something that is extremely brief or compact.
She wore an ultrashort dress to the party.
Ultrashort is formed from "ultra-" (meaning beyond or extreme) and "short" (meaning having little length). The word ultrashort describes something that is extremely short in length or duration.
Think of 'ultra-' meaning beyond or extreme, and 'short' meaning little length — together they describe something that is extremely short.
No commonly confused words.