Sentence:  These booze customers had until then been <WSD>buying</WSD> their supplies from the Sheldon , Saltis-McErlane , and Druggan-Lake gangs , and now they were competing for trade with the Torrio-Capone saloons ; once again O ' Banion 's brash recklessness had caused a proliferation of ill will . 
Meaning of the word marked with <WSD> tags:  obtain by purchase; acquire by means of a financial transaction