余割

cosecant (of angle), written cosec θ or csc θ

surname Yu

(archaic) I / me / variant of 餘|余[yu2], surplus

extra / surplus / remaining / remainder after division / (following numerical value) or more / in excess of (some number) / residue (math.) / after / I / me

to cut / to cut apart

hyperbolic cosecant, i.e. function cosech(x)