The story
- Old Norse · derived fromþykkna“to thicken”
- Middle English · inherited fromthickenen
- English todaythicken
From 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 4.0.