February 23 is Brunei's National Day, involving a big parade in the National Stadium. In connection with preparations for this parade, I have recently often seen the word raptai ('dress rehearsal') in the Media Permata. Surprisingly, raptai is absent from my dictionary (Collins Easy Learning Dictionary), which is a bit surprising as it seems to be a reasonably common word. Fortunately, it is included in the excellent Pusat Rujukan Persuratan Melayu, together with some helpful examples of its usage. I guess printed dictionaries are on the way out, and nowadays everyone uses web-based sources.
One other thing about raptai is how it should be pronounced. Is it two syllables, like cukai ('tax')? Or is it three syllables like mulai ('begin')? There is no way to tell from the spelling, which illustrates the limitations of the Malay spelling system. For it to be three syllables, the final 'i' would have to be a suffix; but there is no way to tell if the root of the word is rapta or not.
I have subsequently heard it spoken on the Nasional FM radio news, and it seems to be two syllables; so it is a single morpheme.