From Longman Dictionary of Contemporary Englishunsoundun‧sound /ˌʌnˈsaʊnd◂/ adjective 1 TRUEnot based on facts or good reasonsideologically/scientifically/ecologically etc unsound a test that’s scientifically unsound2 CONDITION/STATE OF somethingan unsound building or structure is in bad condition The houses are structurally unsound.3 CRAZY formal physically or mentally ill people of unsound mind (=people who are mentally ill)
Examples from the Corpus
unsound• Again I suggest that this line of argument is unsound.• When they found that this was impossible, they turned their backs on religion and declared its teachings to be unsound.• He claimed that the site was geologically unsound and any stress caused by a shift in water levels could cause an earthquake.• unsound banking practices• Some attacked the fact that faster growth has been environmentally unsound, creating excessive carbon emissions and destroying natural habitats.• In the summer of 1913 Chapman at last turned his attention to City's unsound defence.• Cassie entertained more than a suspicion that John would definitely prove to be very ideologically unsound indeed!• Around 1902 the Leversons lost money through an unsound investment.• If, then, the Member is still of unsound mind, his seat is automatically vacated.ideologically/scientifically/ecologically etc unsound• I would go further and suggest that it is also ideologically unsound.• Also, many names are painted on the bottom of the routes - ecologically unsound, but convenient!• It was expensive, high tech, brutal and, I don't doubt, ecologically unsound but I loved it all.• Cassie entertained more than a suspicion that John would definitely prove to be very ideologically unsound indeed!structurally unsound• They were often structurally unsound and costly to maintain, hard to staff because of their physical isolation and far too big.• Today there are very few old buildings so structurally unsound that they can not be saved.of unsound mind• If, then, the Member is still of unsound mind, his seat is automatically vacated. 