COSY MAS NMR, also known as Coherence Transfer through Zero-Quantum Magnetic Resonance Spectroscopy, is a technique widely used in nuclear magnetic resonance (NMR) spectroscopy. It offers a unique way to study molecular structures and interactions. However, if you're in search of synonyms for the term, "cosy" can also be referred to as "comfortable", "snug" or "homey". As for "MAS NMR", it stands for "Magic Angle Spinning Nuclear Magnetic Resonance", and similar phrases that convey the same meaning include "rotor-based NMR" or "spinning NMR". Broadly speaking, these terms all refer to various aspects of the same scientific technique used in the field of NMR spectroscopy.