| Acronym | Meaning |
| HFMD | Hellmann-Feynman Mol.-dynamics (method In Electronic Structure And Geometry Calcns.) |
| HFO | Hartree-Fock Orbital |
| HFO | Hydrous Ferric Oxide |
| HFP | Hartree-Fock (plus) Pauli (terms) |
| HFP | Hartree-Fock Perturbation |
| HFPD | Hartree-Fock With Proper Dissociation (wave Function) |
| HFPP | Hartree-Fock Pseudopotential |
| HFPT | Hartree-Fock Perturbation Theory |
| HFRP | Hybrid Fiber Reinforced Plastics |
| HFRR | High Frequency Reciprocating Rig |
| HFRSPT | Hartree-Fock Rayleigh-Schroedinger Perturbation Theory |
| HFRW | High Frequency Resistance Welding |
| HFS | Hartree Fock Slater |
| HFS | Hyperfine Structure |
| HFSE | High Field Strength Element(s) |
| HFSLM | Hollow-fiber Supported Liquid Membrane |
| HFWG | Hollow Fiber Waveguide |
| HG-AAS | Hydride Generation-at. Absorption Spectroscopy |
| HGAAS | Hydride Generation Atomic Absorption Spectrometry |
| HGAFS | Hydride Generation Atomic Fluorescence Spectrometry |
| HGCU | Hot Gas Cleanup |
| HGCU | Hot-gas Particulate Cleanup |
| HGCU | Hot-gas-cleanup Unit |
| HGDB | Hydrogeologic Database |
| HGF | Hermite Gaussian Function |
| HGF | Hepatocyte Growth Factor |
| HGG | Hot Gas Generator |
| HGH | Human Growth Hormone |
| HGHR | Human Growth Hormone Receptor |
| HGMD | Human Gene Mutation Database |
| HGMF | High Gradient Magnetic Filtration |
| HGMIS | Human Genome Management Information System |
| HGMS | High Gradient Magnetic Separation (for Water Treatment) |
| HGNC | HUGO Gene Nomenclature Committee |
| HGP | Human Genome Project |
| HGP | Hepatic Glucose Production |
| HGRF | Human Growth Hormone-releasing Factor |
| HGSI | The Human Genome Sequencing Index |
| HGTF | Hermite Gaussian-type Function |
| HH-GLF | Hyperspherical Harmonic-generalized Laguerre Function |
| HHAP | Heavy Hydroaroms. From Petroleum |
| HHE | Health Hazard Evaluation |
| HHG | High-order Harmonic Generation |
| HHH | Henon-Heiles Hamiltonian |
| HHMI | Howard Hughes Medical Institute |
| HHOB | High-energy Higher-order Born (approxn. For Scattering Calcns.) |
| HHPN | Hydraulic High Pressure Nebulization |
| HHS | Health And Human Services Department |
| HHW | Household Hazardous Waste |
| HI | Hinkley Index |