gerna -gen ge'a- gismu

x1 is the grammar/rules/defining form of language x2 for structure/text x3.

See also bangu, stura, cmavo, jufra.

In notes:

bangu
x1 is a/the language/dialect used by x2 to express/communicate x3 (si'o/du'u, not quote).
cmavo
x1 is a structure word of grammatical class x2, with meaning/function x3 in usage (language) x4.
fletola
x1 (property of x3) is the grammar of language x2 for elidible construct x3 that is assumed to fill its place even if elided
gensu'a
s1 is a grammatical structure/syntax of text s2=g3 defined by the grammar g1 of language g2.
gentufa
x1 parses text x2 using grammar x3
gretera
x1 (property of x3) is the grammar of language x2 for construct x3 that can be optionally added changing the meaning of the initial construct without it
jo'au (exp!)
change version/dialect of parser
jufra
x1 (text) is a sentence/statement about x2 [topic/subject/predicate/focus] in language x3.
lenguua
x1 is a language used by x2 to express x3 (du'u, not quote)
nutko
x1 is the language/sublanguage that uses no apparent terbri/selbri distinction and is used by x2 to express ideas (not text) x3.
pirxo
x1 is the language/sublanguage that uses no apparent recursion rules and is used by x2 to express ideas (not text) x3.
stura
x1 is a structure/arrangement/organization of x2 [set/system/complexity].
terkemseldumterbau
x1 is a language/dialect used by x2 to express/communicate x3 (text, not clause)
turbaro
x1 (text) grammatically expands to x2 (text)
uenzi
x1 is an utterance or text about x2