Merriam-Webster and Wiktionary/Wikipedia give somewhat different definitions for these two terms, so I was wondering which one is correct?

Wiktionary defines candelabrum and candelabra like this:

http://en.wiktionary.org/wiki/candelabrum

1. A candle holder.

http://en.wiktionary.org/wiki/candelabra

1 Plural form of candelabrum.

2 (common usage, though somewhat incorrect) a single candelabrum

And Merriam-Webster like this:

http://www.merriam-webster.com/dictionary/candelabrum

: candelabra

http://www.merriam-webster.com/dictionary/candelabra

: a branched candlestick or lamp with several lights
You can consider a branched candlestick as either singualr or plural, it seems to me. In addition, relatively few native speakers realize that candleabra is plural. No doubt the distinctive singular will disappear in a few decades.
Thanks.

So in other words, you'd say Wiktionary is technically correct in defining 'candelabrum' as the multi branched candlestick, but in general usage 'candelabra' is the prevalent form, although somewhat incorrect?

Also, would the plural of candelabra be 'candelabras' in common usage?
Students: Are you brave enough to let our tutors analyse your pronunciation?
Wiktionary is technically correct in defining 'candelabrum' as the multi branched candlestick-- Yes.

but in general usage 'candelabra' is the prevalent form, although somewhat incorrect?-- Yes, that's right.

Also, would the plural of candelabra be 'candelabras' in common usage?-- Yes, indeed.
Thanks a lot!