Jean calling eren suicidal blockhead is just
Suicidal blockhead or suicidal moron is the team's (eren, mikasa, Jean, armin, sasha, Connie, reiner, etc) nickname to Eren when they were still training and newbies in the survey corps. So it's heartbreaking when Jean calls him that again after so many years. And yes they are right about the nickname coz he really is a suicidal moron.
You're fxxked fr noah