Emily Dickinson Lexicon

THICK-EN, v.t. [thik'n; Sax. thiccian.]

1. To make thick or dense.
2. To make close; to fill up interstices; as, to thicken cloth.
3. To make concrete; to inspissate; as, to thicken paint, mortar or a liquid.
4. To strengthen; to confirm. And this may help to thicken other proofs. [Not used.] Shak.
5. To make frequent, or more frequent; as, to thicken blows.
6. To make close, or more close; to make more numerous; as, to thicken the ranks.