ist.i                PRON   6 1 DAT S X                 
ist.i                PRON   6 1 NOM P M                 
iste, ista, istud  PRON   [XXXAX]  
that, that of yours, that which you refer to; such;
ist.i                PRON   3 1 NOM P M                 
istic, istaec, istoc  PRON   [XXXDX]    lesser
that of yours/mentioned by you/at hand;
isti                 ADV    POS                         
isti  ADV   [XXXDX]    lesser
there, in that place; where you are; herein, in this affair;
Syncope   s => vis   
Syncopated perfect often drops the 'v' and contracts vowel
iv.isti              V      6 1 PERF ACTIVE  IND 2 S    
eo, ire, ivi(ii), itus  V   [XXXAX]  
go, walk; march, advance; pass; flow; pass (time); ride; sail;