First of all, this word is used in Modern Hebrew, but it's borrowed from Aramaic.
The Hebrew root it's related to is ד.ו.ק (d.v.k), which has to do with thinness. The word דַּק (dahk) means fine or slight, or subtle. The root also gives rise to the words לְדַיֵּק (le-dah-YEHK) - to be precise; and דִּקְדּוּק (deek-DOOK) - grammar.
So what does דַּוְקָא () actually mean? Here's what the online dictionary, Morfix, has to say: