thicken

Verb

thicken (third-person singular simple present thickens, present participle thickening, simple past and past participle thickened)

1. (transitive) To make thicker (in the sense of wider).

   Synonyms:

   broaden

2. (transitive) To make thicker (in the sense of more viscous).
   • to thicken a sauce
3. (intransitive) To become thicker (in the sense of wider).
   • As we age, the major arteries of our bodies frequently become thickened with plaque, a fatty material with an oatmeal-like consistency that builds up along the inner lining of blood vessels. The reason plaque forms isn’t entirely known, but it seems to be related to high levels of cholesterol...2013 July-August, Stephen P. Lownie, David M. Pelz, “Stents to Prevent Stroke”, in American Scientist
4. (intransitive) To become thicker (in the sense of more viscous).

   Synonyms:

   inspissate

5. (transitive) To strengthen; to confirm.
   • And this may helpe to thicken other proofes,/ That do demonstrate thinly.c. 1603–1604 (date written), William Shakespeare, “The Tragedie of Othello, the Moore of Venice”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac...

   Synonyms:

   build up

6. (transitive) To make more frequent.
   • to thicken blows
7. (literary) To make more detailed or comprehensive.