PTS Pali-English dictionary - The Pali Text Society's Pali-English dictionary
Mūsī
Mūsī,(f.) [Venic mūṣ & mūḥ mouse or rat; cp.Lat.mūs Gr.mu_s,Ohg.mūs=E.mouse.Not to muṣ to steal,but to same root as Lat.moveo,to move] a mouse S.II,270 (mudu° a tender,little m.).(Page 540)