"We met this semester."
Translation:Ci siamo conosciuti questo semestre.
Semestre is not much use to you in Italy. It means "half-year", or tells everyone you are American. (Useful to know in a hostage situation :-)
Educationally, Italy (together with much of Europe, and Canada) uses three trimestre, which translate to "terms". In Italy they are called Primo, Secondo and Terzo. Brits call them Autumn, Spring and Summer, even though the spring term is mostly in (meteorological) winter, and half the summer term is in spring. What a country.
Oz and NZ use a four term system (quattrimestre? - no idea) helpfully called terms 1, 2, 3 and 4.
Italy does not have a unified schedule at university/college level, and in actual Italian universities 3 months courses are the exception, not the rule. The two most common schedules are yearly and, indeed, semestrali; despite the name, they don't take a whole year or 6 months, e.g. in my university the 1st semester had courses from October to December with 3 exam sessions in January and February, and the 2nd semester had courses from March to May with 3 exam sessions in June and July (then two additional exam sessions in September for those who couldn't pass them earlier). I've been told that some specialised schools (e.g. Politecnico) used a 1 month approach, with exams right after a single course; I personally don't know of a single university using a 3 months schedule.
Three trimesters were used in primary schools before the 70s, but nowadays most of them are divided in two quadrimesters, with a general evaluation (pagella) at the end of each, and the second one being decisive for being admitted to the next year, but courses are yearly: the division is more of a checkpoint. Middle and secondary schools are typically yearly, from September to June, with an evaluation in June. Even though there is only one term, there are large holiday periods around Christmas (schools typically close for at least 2 weeks) and Easter (1 week).
We met this semester implies we met each other for the first time - which in italian would be ci siamo conosciuti. Abbiamo incontrato also means we met, but implies that you already knew each other - met as in ran into or got together - but not for the first time.
I think that's why DL only accepts conoscere.