sinking fund

money put aside by a government or company, etc to be used to repay a debt gradually （政府、 公司等准备的）偿债基金.

sinfully, sing, Singapore, singe, singer, singing, single, single out, single-minded, singlet, singsong, singular, singularity, singularly, sinister, sink, sink in, sinker, sinkhole, sinking, sinlessness, sinner, Sino- (also sino-), sinologist, sinology, sinuosity, sinuous, sinus, sinusitis, sip, siphon, sir, sire, siren, sirloin, sirocco, sirup, sisal, sissy (also cissy), sister,