From Longman Dictionary of Contemporary Englishsawbucksaw‧buck /ˈsɔːbʌk $ ˈsɒː-/ noun [countable] American English old-fashioned informal PECa piece of paper money worth $10Origin sawbuck (1800-1900) sawbuck “sawhorse” ((19-20 centuries)), from Dutch zaagbok; probably because the end of some types of sawhorse looks like a Roman number X (= 10)
