7 letters · 16 points in Scrabble
verb make thick or thicker
verb become thick or thicker
verb make viscous or dense
originFrom Middle English thickenen, thikkenen, perhaps from Old Norse þykkna (“to thicken”); equivalent to thick + -en. Cognate with Swedish tjockna (“to thicken”), Icelandic þykkna (“to thicken”).
Etymology from Wiktionary, CC BY-SA 3.0