Definition of "cook up"

cook up

verb
third-person singular simple present cooks up, present participle cooking up, simple past and past participle cooked up
1. (transitive) To prepare (food or chemical substances) by cooking or heating.
2. (transitive, figuratively) To manufacture; to invent (something, often a deceit or falsehood).
  Quotations
  For more than two years Thailand's ruling junta, which seized power in a coup in 2014, has been cooking up a constitution which it hopes will keep military men in control even after elections take place.
  2017 January 14, “Thailand's new king rejects the army's proposed constitution”, in The Economist‎
  "RMT will not sit back while this carve-up of the rail network is cooked up in company boardrooms. [...]".
  2021 September 8, “RMT on "war footing" in response to workforce cutback threats”, in RAIL, number 939, page 15
3. (slang) To prepare a heroin dose by heating.
4. (slang) To manufacture a significant amount of illegal drugs (LSD, meth, etc.)
5. Used other than figuratively or idiomatically: see cook,‎ up.