Marijuana Horticulture: The Indoor/Outdoor Medical Grower's Bible

propagation.
    gene pool: collection of possible gene combinations in an available population
    genetic makeup: the genes inherited from parent plants: Genetic makeup is the most important factor dictating vigor and potency.
    genotype: specific genetic makeup of an individual, which determines the physical appearance of that individual
    germplasm: the sum total of the genetic or hereditary materials in a species
    gibberellin: a class of plant growth hormone used to promote stem elongation: Gibberellic acid is a form of gibberellin.
    girdling: removing a strip of bark or crushing the stem of a plant. Girdling limits the flow of nutrients, water, and plant products, which can kill the plant.
    glandular trichome: plant hair gland which secretes resin
    gpm: gallons per minute
    green lacewing: insect that preys on aphids, thrips, whiteflies, etc, and their larva and offspring
    greenhouse: a heated structure with transparent/translucent walls and ceiling which offer some environmental control to promote plant growth

Girdling
    guano: dung from birds, high in organic nutrients: Seabird guano is noted for being high in nitrogen, and bat guano is high in phosphorus.
    gynoecious: an individual plant having all pistillate flowers: in reference to a population, all-female
    gynoecium: female part of a flower that consists of one or more pistils
    halide: binary chemical compound of a halogen(s) with an electropositive element(s)
    halogen: any of the non-metallic elements fluorine, chlorine, bromine, iodine, and astatine existing in a free state: Halogens are enclosed within the arc tube of a metal halide lamp.
    hardening-off: gradual adaptation of indoor or greenhouse plants to an outside environment
    hashish/hash: a psychoactive drug formed of compressed resin heads of glandular trichomes shaken, washed, or rubbed from cannabis foliage
    hash oil: solution of tetrahydrocannabinol with a high THC content; made from cannabis
    hemp: fibrous cannabis low in THC, used to make a menagerie of products from textiles to automobiles
    hermaphrodite: an individual having flowers of both sexes on the same plant. Hermaphrodites are more correctly referred to as “intersex.”
    Hertz (Hz): a unit of a frequency that cycles one time each second: A home with a 60 hertz AC current cycles 60 times per second.
    heterosis: hybrid vigor such that an F1 hybrid falls outside the performance range of the parents with respect to some character or characters: usually applied to size, rate of growth, or general vigor
    heterozygous loci: regions along homologous chromosome that have different alleles
    HID: High Intensity Discharge lamp: This is the type of lamp used in many indoor grow rooms.
    homologous chromosomes: members of paired chromosomes in non-gametic cells; homologous chromosomes are similar in size, shape, and, supposedly, in function. One of each of the homologous chromosomal pair is derived from the male parent, the other from the female.
    honeydew: a sticky honey-like substance secreted onto foliage by aphids, scale, and mealy bugs
    hood: the reflective cover of a lamp
    HOR: the abbreviation stamped on some HID bulbs meaning they may be burned in a horizontal position
    hormone: chemical substance that controls the growth and development of a plant: Root-inducing hormones help clones root.
    horticulture: the science and art of cultivating plants
    hose bib: water outlet usually found outdoors that contains an on/off valve
    hostile environment: environment that is unfriendly and inhospitable to pests and diseases
    humidity, relative: ratio between the amount of moisture in the air and the greatest amount of moisture the air could hold at the same temperature
    humus: dark, fertile, partially decomposed plant or animal matter: Humus forms the organic portion of the soil.
    hybrid: an offspring from two plants of different breeds, variety, or genetic make-up
    hybrid vigor: greater strength and health or faster rate of growth in the offspring resulting from the cross-breeding of two gene pools

Hybrid vigor.
    hybridizing: see cross-pollination
    hydrogen: light, colorless, odorless, highly flammable gas: Hydrogen combines with oxygen to form water.
    hydroponics: growing plants in nutrient solutions without soil, usually in an inert soilless mix
    hygrometer: instrument for measuring relative humidity in the atmosphere: A hygrometer will save time, frustration, and money.
    IAA: Indol-eacetic acid, a plant hormone that stimulates growth
    IBL: inbred