catch and release /kætʃ ənd ɹəˈliːs/ noun5 •A variety of angling where the fish are released after capture, as a conservation measure. •The immigration policy of releasing illegal immigrants while they await a hearing, rather than detaining them. •The practice by police of apprehending someone but then letting them go without making an arrest. •The practice of replacing artifacts in their original location after examining and cataloguing them. •The practice of a patent holding company buying a patent, offering a license to its members, and then selling or donating the patent after a certain period.