When I saw this extract from an article about electricity generation in Malaysia on page 9 of Media Permata of 26 April, 2011, I knew that rizab must be a borrowed word, as /z/ only occurs in borrowed words, such as zakat ('tithe'), and zaman ('era') that come from Arabic, and zon ('zone') and zink ('zinc') from English, and also because /b/ cannot occur at the end of a native word in Malay.But what does rizab mean?
It turns out that it comes from the English reserve. Note that the final /v/ in English becomes /b/ in Malay, just like in arkib ('archive').
What contributed to my failure to identify the word as coming from reserve is the omission of the second 'r'. If arkib keeps the 'r' from English, why does rizab not?
My colleague, Adrian Clynes, suggests it is because 'r' is fine as a part of a medial cluster, but not as part of a final cluster. So maybe that is the explanation.
One other thing about rizab: I showed it to some Bruneian students and colleagues, and none of them knew what it meant. Maybe it only exists in Malaysian Malay, not in Brunei.