chassis

I based my response on the entry for κάψις in the Perseus version of Liddell & Scott's Greek Lexicon [1]. It also has κατάποσις [2], but doesn't have any sense meaning "little box". I have a hunch that you're using modern or medieval Greek, which have quite a few loanwords from Latin, and that καψις meaning "little box" is one of them. Please see WT:AGRC and WT:AEL about where we draw the distinction between ancient and modern Greek, and the proper way to format them in etymologies.