Connections Hint Today Thu, May 15 #745

Need help with Connections puzzle #745 on Thu, May 15? Get your daily connections hint today! Find the hidden links between these 16 words: BASIS, FOUNDATION, GROUNDS, REASON, CRUST, ICE, POWDER, SLUSH, BESS, BUTTERFLY, FLUTE, SEVILLE, DEAL, ESTATE, MADRID, WORLD