noun

• (US, Philippines, accounting) Initialism of certified public accountant. [An accountant who has met certain legal requirements to provide certain accounting services.]
• (Canada, accounting) Initialism of chartered professional accountant.
• (accounting) Abbreviation of collaboration protocol agreement in ebXML.
• (chemistry) Initialism of copolymer alloy.
• (nautical, aviation) Initialism of closest point of approach. [(nautical, navigation) An estimated point in which the distance between two objects, of which at least one is in motion, will reach its minimum value; abbreviated CPA. The estimate is used to evaluate the risk of a collision of e.g. two ships.]
• (pathology) Initialism of chronic pulmonary aspergillosis.
• (organic chemistry, pharmacology) Abbreviation of cyproterone acetate. [(organic chemistry, pharmacology) The cyproterone ester of acetic acid that is an antiandrogen and progestin medication - C₂₄H₂₉ClO₄.]
• (Semitistics) Abbreviation of Christian Palestinian Aramaic.
• (computer security) Abbreviation of correlation power analysis.
• (computer security) Abbreviation of chosen-plaintext attack. [(cryptography) An attack on a cryptosystem that relies on the attacker's ability to choose any plaintext of their liking and encrypt it into the corresponding ciphertext with that system and key. More powerful than a known-plaintext attack but less powerful than a chosen-ciphertext attack.]
• (advertising) Abbreviation of cost per action.
• (metascience) Abbreviation of co-citation proximity analysis.