English abbreviations from cosine to cotac
- COSINE (Cooperation for OSI Networking in Europe)
- COSIS (Care Of Supplies In Storage)
- COSL (Council of School Leaders)
- COSLA (Chief Officers of State Library Agencies)
- COSM (Composite Object Sound Modelling)
- COSMIC (Common Software Measurement Consortium)
- COSMOS (Community-Oriented Science and Mathematics Opportunities For Students)
- COSO (Committee Of Sponsoring Organizations)
- COSPAR ((organization) COmmittee on SPAce Research)
- COSPAS (COsmicheskaya Sistyema Poiska Avariynch Sudov (Space System for Search of Distressed Vessels (Russian Satellite System)))
- COSR (Combat and Operational Stress Reactions)
- COSS. (Consules ("Consuls"))
- COSS (Common Object Services Specification)
- COST (Community Outreach Service Team)
- COSTAR ((instrumentation) Corrective Optics Space Telescope Axial Replacement, corrective optics for the Hubble Space Telescope)
- COSYMA (COSYnthesis for eMbedded Architectures)
- COT (Commissioned Officer Training)
- COTA (Celebration Of The Arts)
- COTA(A) (Council on the Ageing (Australia))
- COTAC (Conduite de Tir Automatique pour Char (tank automatic fire))