heav·y 
(hĕvē)
(hĕvē)adj. heav·i·er, heav·i·est
1. Having relatively great weight: a heavy load.
2. Having relatively high density; having a high specific gravity.
3.
a. Large, as in number or quantity: a heavy turnout; heavy casualties.
b. Large in yield or output: heavy rainfall.
4. Of great intensity: heavy activity; heavy fighting.
5.
a. Having great power or force: a heavy punch.
b. Violent; rough: heavy seas.
6.
a. Equipped with massive armaments and weapons: a heavy cruiser; heavy infantry.
b. Large enough to fire powerful shells: heavy guns.
7.
a. Indulging to a great degree: a heavy drinker.
b. Involved or participating on a large scale: a heavy investor.
8. Of great import or seriousness; grave: heavy matters of state.
9.
a. Having considerable thickness: a heavy coat.
b. Broad or coarse: drew the face with heavy lines.
10.
a. Dense; thick: a heavy fog.
b. Slow to dissipate; strong: "There was a heavy fragrance of flowers and lemon trees" (Mario Puzo).
c. Too dense or rich to digest easily: a heavy dessert.
d. Insufficiently leavened: heavy bread.
e. Full of clay and readily saturated: heavy soil.
11.
a. Weighed down; burdened: trees heavy with plums.
b. Emotionally weighed down; despondent: a heavy heart.
c. Marked by or exhibiting weariness: heavy lids.
d. Sad or painful: heavy news.
12.
a. Hard to do or accomplish; arduous: heavy going; heavy reading.
b. Not easily borne; oppressive: heavy taxes.
13. Lacking vitality; deficient in vivacity or grace: a heavy gait; heavy humor.
14. Sharply inclined; steep: a heavy grade.
15. Having a large capacity or designed for rough work: a heavy truck.
16. Of, relating to, or involving the large-scale production of basic products, such as steel: heavy industry.
17. Of or relating to a serious dramatic role.
18. Physics Of or relating to an isotope with an atomic mass greater than the average mass of that element.
19. Loud; sonorous: a heavy sound; heavy breathing.
20. Linguistics Of, relating to, or being a syllable ending in a long vowel or in a vowel plus two consonants.
21. Slang
a. Of great significance or profundity.
b. Very popular or important: a rock star who is really heavy.
adv. heav·i·er, heav·i·est
Heavily: The snow is falling heavier tonight than last night.
n. pl. heav·ies
1.
a. A serious or tragic role in a play.
b. An actor playing such a role.
2. Slang A villain in a story or play.
3. Slang A mobster.
4. Slang One that is very important or influential: a media heavy.
[Middle English hevi, from Old English hefig; see kap- in the Appendix of Indo-European roots.]
heavi·ness n.
Synonyms: heavy, weighty, hefty, massive, ponderous
These adjectives mean having a relatively great weight. Heavy refers to what has great physical weight (a heavy boulder) and figuratively to what is burdensome or oppressive to the spirit (heavy responsibilities). Weighty literally denotes having considerable weight (a weighty package); figuratively, it describes what is onerous, serious, or important (a weighty decision). Hefty refers principally to physical heaviness or brawniness: a hefty book; a short, hefty wrestler. Massive describes what is bulky, heavy, solid, and strong: massive marble columns. Ponderous refers to what has great mass and weight and usually implies unwieldiness: ponderous prehistoric beasts. Figuratively it describes what is complicated, involved, or lacking in grace: a book with a ponderous plot.
These adjectives mean having a relatively great weight. Heavy refers to what has great physical weight (a heavy boulder) and figuratively to what is burdensome or oppressive to the spirit (heavy responsibilities). Weighty literally denotes having considerable weight (a weighty package); figuratively, it describes what is onerous, serious, or important (a weighty decision). Hefty refers principally to physical heaviness or brawniness: a hefty book; a short, hefty wrestler. Massive describes what is bulky, heavy, solid, and strong: massive marble columns. Ponderous refers to what has great mass and weight and usually implies unwieldiness: ponderous prehistoric beasts. Figuratively it describes what is complicated, involved, or lacking in grace: a book with a ponderous plot.