* Gram (unit of weight)
* Grammar (rules of language)
* Grammarian (one who studies grammar)
* Gramophone (a device for playing phonograph records)
* Grammatically (in accordance with the rules of grammar)
* Grammatical (relating to grammar)
* Gramme (an alternative spelling of gram)
* Gramp (a grandfather)
* Grampus (a type of dolphin)
* Granary (a storehouse for grain)
* Grandiose (impressive in scale or scope)
* Granola (a breakfast cereal made from rolled oats)
* Grant (to give something formally)
* Graphic (relating to visual art)
* Graphite (a soft form of carbon)
* Grapple (to engage in close combat)
* Gratis (free of charge)
* Gratitude (thankfulness)
* Grave (a place for burying the dead)
* Gravel (small stones)
* Gravity (the force that attracts objects towards each other)
* Gray (a shade of color)
* Graze (to eat grass)
* Grease (a thick oil)
* Great (large or important)
* Green (a color)
* Greet (to welcome)
* Gregarious (fond of company)
* Grief (intense sorrow)
* Grill (a metal frame used for cooking)
* Grim (serious or gloomy)
* Grind (to crush into small particles)
* Grip (to hold firmly)
* Groan (a low sound of pain or distress)
* Gross (total or whole)
* Ground (the surface of the earth)
* Group (a collection of people or things)
* Grove (a small group of trees)
* Grow (to increase in size)
* Growth (the process of increasing in size)
* Guarantee (a promise of something)
* Guard (to protect)
* Guess (to form an opinion without sufficient information)
* Guest (a person visiting someone)
* Guide (to direct or lead)
* Guild (an association of people with similar interests)
* Guilty (responsible for a crime)
* Guitar (a musical instrument)
* Gull (a type of seabird)
* Gulp (to swallow quickly)
* Gum (a sticky substance)
* Gun (a weapon that fires bullets)
* Gymnasium (a place for physical exercise)
* Gynecologist (a doctor specializing in women's health)
This is not an exhaustive list, but it covers a wide range of words with the "gram" prefix.