| Acronym | Meaning |
| RRHO | Rigid Rotor-harmonic Oscillator (approxn.) |
| WINDS | Wideband Internetworking Engineering Test And Demonstration Satellite |
| LADD | Lifetime Average Daily Dose |
| ECP | Eosinophil Cationic Protein |
| NORA | National Occupational Research Agenda |
| RAM | Reference-system Average Mayer-function (in Perturbation Theory) |
| DDRPA | Double Direct Random Phase Approximation |
| DPE | Dual-phase Extraction |
| STHF | Single-term Hartree-Fock |
| ERW | Electrical Resistance Welding |