Yuganaddha A method of meditative practice where, in alternating sequence, tranquillity-meditation and insight-meditation are developed. It is called 'tranquillity and insight joined in pairs' samatha-vipassanāyuganaddha the coupling or yoking of tranquillity and insight. He who undertakes it, first enters into the 1st absorption. After rising from it, he contemplates the mental phenomena that were present in it feeling, perception, etc. as impermanent, painful and no-self, and thus he develops insight. Thereupon he enters into the 2nd absorption; and after rising from it, he again considers its constituent phenomena as impermanent, etc. In this way, he passes from one absorption to the next, until at last, during a moment of insight, the intuitive knowledge of the path of Stream-entry, etc. flashes forth - See A. IV, 170; A.IX, 36; Pts: Yuganaddha Kathā.
Maha Thera Nyanatiloka. Manual of Buddhist Terms and Doctrines, Buddhist Publication Society, first edition 1952.