| Acronym | Meaning |
| HEGO | Heated Exhaust Gas Oxygen |
| GEK | Geomagnetic Electrokinetograph |
| OPP | Office Of Pesticide Programs |
| CIOS | Classical Infinite Order Sudden (in Atom-mol. Reaction Calcns.) |
| DRP | Dense Random Packing |
| PAF | Platelet Activating Factor |
| CC-DQMC | Clamped-coordinate Diffusion Quantum Monte Carlo |
| BOO | Bond Order Orbital |
| QBO | Quasi-biennial Oscillation (atm.) |
| POS | Points-on-a-sphere (repulsion Potential Model |