tri                  PREFIX                             
three; (also used to represent many times, persistant, extreme, gross);
tus                  SUFFIX                             
of _; from the _;
stus                 ADV    POS                         
him/her/it/ones-self; him/her/it; them (selves) (pl.); each other, one another;
us                   SUFFIX                             
-ly;
tristus              ADV    POS                         
tristis, tristis, triste  ADJ   [XXXAX]  
sad, sorrowful; gloomy;