silver in the form of ingots, usually bearing the stamp of a banker or assayer, formerly used in China as money
See sycee in American Heritage Dictionary 4
sy·cee
noun
Lumps of pure silver bearing the stamp of a banker or an assayer and formerly used in China as money.
Origin: Chinese (Cantonese) saìsz, fine silk (so called because the pure silver can be spun into fine threads), equivalent to Chinese (Mandarin) xì, thin, fine + Chinese (Mandarin) sī, silk, thread.