Nulathoe’s Ninemen – what does “Ninemen” mean?

Every reference to this spell of Ed Greenwood’s makes sure to note that "ninemen" is pronounced "nin-em-en" rather than "nine men," making it a unique word of some sort. I’m just curious whether this is some archaic word I’ve never run into, or whether any canonical source (even just Ed Greenwood’s say-so) defines this term. Does anyone have any insight?