Sōpagon is an uninflected High Valyrian word for to laugh. Thirat atthiraride is an uninflected Dothraki expression for to dream (more literally "to live a false life"). We might suspect that this isn't very serious attempt at creating text. That being said, given the Dothraki zero-copula syntaxes, the sentence
Sōpagon thirat atthiraride.
could be taken as a person telling in Dothraki what sōpagon means. If we replace Valyrian with Latin and Dothraki with English, we get
'Rirendi' is 'to dream'.
Viewing laughing as a delusional and foreign thing to do cuts close to home, considering GRRM's world.
