Word mod s -> ss     
A doubled consonant may be rendered by just the single  MEDIEVAL
crass.is             N      2 1 LOC P M                 
crass.is             N      2 1 DAT P M                 
crass.is             N      2 1 ABL P M                 
Crassus, Crassi  N (2nd) M   [XXXDX]    lesser
Crassus; (Roman cognomen); [M. Licinius Crassus Dives => triumvir];
crass.is             ADJ    1 1 DAT P X POS             
crass.is             ADJ    1 1 ABL P X POS             
crassus, crassa -um, crassior -or -us, crassissimus -a -um  ADJ   [XXXAO]  
thick/deep; thick coated (w/ABL); turbid/muddy (river); dense/concentrated/soli
fat/stout; rude, coarse, rough, harsh, heavy, gross; stupid, crass/insensitive;