Islamist /ˈɪsləmɪst/noun 3adjective 2forms 3 noun3 •A Muslim who espouses Islamic fundamentalist beliefs. •A scholastic Muslim who specializes in Muslim academics. •(no longer used) A Muslim. adjective2 •Motivated by fundamentalist Muslim beliefs, particularly in the political sphere.In January, Boko Haram struck Fotokol, a Cameroonian town separated by only a bridge from Gambarou, Nigeria, a stronghold of the Islamist extremists. The attackers killed more than 400 people. — 2015 •(old-fashioned) Relating to Islam; Islamic, Muslim. formsIslamists · more Islamist · most Islamist