From Proto-Italic *semtīna, from Proto-Indo-European *semH- (“to scoop”). Cognate with Proto-Celtic *semeti (“to pour”) (compare Middle Welsh gwehynnu (“to pour”), Old Breton douohinnom (“drained”)), Lithuanian sémti (“to pump, scoop”), and possibly Ancient Greek ἀμάομαι (amáomai, “to draw (milk)”). Compare also Ancient Greek ἀντλία (antlía), ἄντλος (ántlos, “bilgewater”).
Practice speaking and memorizing "sentina" and many other words and sentences in Latin.