| Acronym | Meaning |
| SEA WIFS | Sea-viewing Wide Field-of-view Sensor |
| SEAC | Surface-enhanced Affinity Capture |
| SEAM | Superfund Exposure Assessment Manual |
| SEAM | Scanning Electron Acoustic Microscopy |
| SEAMOS | Single-excitations-adapted Molecular Orbitals |
| SEAR | Surfactant-enhanced Aquifer Remediation |
| SEAREX | Sea/Air Exchange Program |
| SEAWIFS | Sea Viewing Wide Field Of View Sensor |
| SEB | Staphylococcal Enterotoxin B |
| SEC | Size Exclusion Chromatography |
| SEC | Scaled External Correlation (extrapolation Method In CI Calcn.) |
| SEC | Sulfite Evaporator Condensate |
| SECH | Screened Exchange Plus Coulomb Hole Method |
| SECI | Single Excitation Configuration Interaction |
| SECM | Scanning Electrochemical Microscopy |
| SECS | Simulation And Evaluation Of Chemical Synthesis |
| SECV | Standard Error Of Cross-validation |
| SECWA | State Energy Commission Of Western Australia |
| SED | Spectral Energy Distribution |
| SED | Surface-conduction Electron-emitter Display |
| SEDAC | Socioeconomic Data And Applications Center |
| SEDEX | Sedimentary Exhalative |
| SEDM | State/EPA Data Management |
| SEDM | Selective Excitation Double Moessbauer |
| SEDOR | Spin-echo Double Resonance |
| SEDRA | Simple Excitation For The Dephasing Of Rotational-echo Amplitudes |
| SEE | Space Environment And Effects |
| SEE | Secondary Electron Emission |
| SEE | Standard Error Of Estimate |
| SEE | Static Exact Exchange (approxn. In Electron-mol. Scattering) |
| SEED | Self Electro-optic Effect Device |
| SEELFS | Surface Extended-energy-loss Fine-structure |
| SEESR | Simultaneous Electrochemical-electron Spin Resonance |
| SEGD | Surfactant-enhanced Gravity Drainage [as Of Subsurface Contaminants] |
| SEGH | Society For Environmental Geochemistry And Health |
| SEGS | Solar Electric Generating System |
| SEHF | Spin-extended Hartree-Fock |
| SEHRRS | Surface Enhanced HyperRaman Resonance Spectroscopy |
| SEHRS | Surface-enhanced Hyper-Raman Scattering |
| SEI | Secondary Electron Imaging |
| SEIRA | Surface-enhanced Infrared Absorption |
| SEL | Stacked Elemental Layer (vapor Deposition Technique) |
| SEL | Surface Emitting Laser |
| SELDI | Surface-enhanced Laser Desorption Ionization Spectrometry |
| SELEX | Systematic Evolution Of Ligands By Exponential Enrichment |
| SEM | Scanning Electron Microscopy |
| SEM | Std. Error Of The Mean |
| SEM | Strategic Environmental Management |
| SEMC | Scaled Ensemble Monte Carlo |
| SEMI | Semiconductor Equipment And Materials Institute |