The phrase "knocksed props out from under" is a colloquialism that means to disrupt or destroy someone's plans or expectations. The word "knocksed" is a phonetic spelling of "knocked" with a strong emphasis on the "ed" sound. In IPA transcription, it would be /ˈnɑksd/, with the stress on the first syllable and the final "d" pronounced as a separate sound. This informal spelling highlights the casual, spoken nature of the phrase and adds to its colloquial charm.