Is there a Chinese word for the idea of “matchmaker?” If so, what is it (roman transliteration, please)?
My Taiwanese associate says the word would be “mae lun” and to pronounce it correctly, you have to say it like it is a question. That is, with an upward lilt. Otherwise, it means something else.
I have no idea what you mean by Roman Transliteration, tho. 
I just meant use the roman alphabet. Which you did. Thank you.
In pinyin, which is the standard romanization method in mainland China, the word for matchmaker is méi ren. The accent on the ‘e’ means that you should pronounce “mei” with a rising tone. “Ren” is flat. The Chinese ‘r’ is a lot like the English ‘r’ sound.
My dictionary also gives the following words:
Bíng rén
Méi pó
Méi shuò
Bíng rén literarily means “ice person” and from what I gather is an expression derived from the name of a legendary(?) matchmaker.
The “pó” in Méi pó means “granny” and so this word probably applies only to older women.
Méi shuò is pronounced baishaku in Japanese and is a somewhat more formal term, I don’t know if it’s the same in Mandarin.
Since my (limited) knowledge of mandarin is almost entirely litterary, I’m not so sure of actual usage.
There are several. In additional to the ones listed, there are:
yue4lao3 - the name of a god who’s in charge of marriages.
hong2niang2 - refers to women exclusively.
P.S. The numerals refer to the tones:
1 - flat
2 - rising
3 - dropping then rising
4 - dipping
5 - light (not pronounced loudly)
Zhuo Mei (sorry, I don’t know the acutal accents). Zhuo = “Do”, Mei =“Marriage”
Xiang Qing = “arranged marriage” (I think, if my hanyu is not off)