jbosnu lujvo

c1 (mass normally, but 1 individual/jo'u possible) discuss(es)/talk(s) about topic/subject c2 in Lojban.

Cf. jbota'a, casnu.

In notes:

jboba'usnu
c1=b1 converses orally in Lojban about subject c2 using sound/expression l1=b2.
jbosku
x1 expresses/says x2 (sedu'u/text) in Lojban, for audience x3, via expressive medium x4.