acerca
/aˈθeɾka/ · A1 · adv
only used in acerca de
a + cerca: to + near, so acerca de = coming near to a topic = about
From Latin ad (to) + circa (around), the same root as English circa. Spanish cerca means near, and acercar means to bring closer. Talking acerca de something is talking close around it, just as English about also means around.