Is the s sound in laciniate written with an s?
soft-cThe c of laciniate is followed by an i, so it goes soft and says s. That single letter is the whole difficulty of the word.
heard aslasiniate
spelledlaciniate
saidluh-SIN-ee-ut
No. It is a c: laciniate.
Soft c is one of the most productive spellings in English and one of the least detectable by ear. Before e, i or y, a c behaves as an s, and lacinia has an i in exactly that position. Nothing you can hear separates this word from a version spelled with an s, which is why lasiniate is the most reasonable wrong answer on the list.
More of the same word
lacciniate laciniat luciniate leciniate lacineate laciniute
Every one of them has an entry. All 9 spellings of laciniate.