Chotto… (ちょっと…): a little… A sentence left unfinished, as in Sono hi wa chotto…, that day is a little…
A Japanese study of refusals calls such forms iisashi, sentences left unfinished. It explains that leaving the end of the sentence unsaid keeps one’s opinion from striking the other person directly. Among the unfinished forms in the study, chotto stood out as especially frequent.