thicken
1 antonym for thicken — opposites grouped by meaning.
Verb — To make something wider or bulkier.
Antonyms
Etymology
From Middle English thickenen, thikkenen, perhaps from Old Norse þykkna (“to thicken”); equivalent to thick + -en. It is cognate with Swedish tjockna (“to thicken”) and Icelandic þykkna (“to thicken”).
Full origin of thicken →