1.  icy(s = adj.all) frigid, frosty, frozen, glacial, wintry - devoid of warmth and cordiality; expressive of unfriendliness or disdain; "a frigid greeting"; "got a frosty reception"; "a frozen look on their faces"; "a glacial handshake"; "icy stare"; "wintry smile"
Derived form noun iciness₂

2.  icy(s = adj.all) arctic, frigid, gelid, glacial, polar - extremely cold; "an arctic climate"; "a frigid day"; "gelid waters of the North Atlantic"; "glacial winds"; "icy hands"; "polar weather"

3.  icy(s = adj.all) - covered with or containing or consisting of ice; "icy northern waters"
Derived forms noun ice₈, noun iciness₁

4.  icy(s = adj.all) - shiny and slick as with a thin coating of ice; "roads and trees glazed with an icy film"
Derived form noun iciness₁

1.  Pertaining to, resembling, or abounding in, ice; cold; frosty. [1913 Webster]

2.  Characterized by coldness, as of manner, influence, etc.; chilling; frigid; cold. [1913 Webster]
"Icy was the deportment with which Philip received these demonstrations of affection." [1913 Webster]

icy, adj. (icier, iciest)
1 very cold.
2 covered with or abounding in ice.
3 (of a tone or manner) unfriendly, hostile (an icy stare).

Derivative:
icily adv. iciness n.

N  cold, coldness, frigidity, inclemency, fresco, winter, depth of winter, hard winter, Siberia, Nova Zembla, wind- chill factor, ice, snow, snowflake, snow crystal, snow drift, sleet, hail, hailstone, rime, frost, hoar frost, white frost, hard frost, sharp frost, barf, glaze, lolly, icicle, thick-ribbed ice, fall of snow, heavy fall, iceberg, icefloe, floe berg, glacier, nev_ee, serac, pruina, freezing mixture, dry ice, liquid nitrogen, liquid helium, chilliness, chill, shivering, goose skin, horripilation, rigor, chattering of teeth, numbness, frostbite, cold, cool, chill, chilly, icy, gelid, frigid, algid, fresh, keen, bleak, raw, inclement, bitter, biting, niveous, cutting, nipping, piercing, pinching, clay-cold, starved, chilled to the bone, shivering, aguish, transi de froid, frostbitten, frost-bound, frost-nipped, cold as a stone, cold as marble, cold as lead, cold as iron, cold as a frog, cold as charity, cold as Christmas, cool as a cucumber, cool as custard, icy, glacial, frosty, freezing, pruinose, wintry, brumal, hibernal, boreal, arctic, Siberian, hyemal, hyperborean, hyperboreal, icebound, frozen out, unwarmed, unthawed, lukewarm, tepid, isocheimal, isocheimenal, isocheimic, frozen, numb, frost-bitten, coldly, bitterly, pierre fendre, cold, coldness, frigidity, inclemency, fresco, winter, depth of winter, hard winter, Siberia, Nova Zembla, wind- chill factor, ice, snow, snowflake, snow crystal, snow drift, sleet, hail, hailstone, rime, frost, hoar frost, white frost, hard frost, sharp frost, barf, glaze, lolly, icicle, thick-ribbed ice, fall of snow, heavy fall, iceberg, icefloe, floe berg, glacier, nev_ee, serac, pruina, freezing mixture, dry ice, liquid nitrogen, liquid helium, chilliness, chill, shivering, goose skin, horripilation, rigor, chattering of teeth, numbness, frostbite, cold, cool, chill, chilly, icy, gelid, frigid, algid, fresh, keen, bleak, raw, inclement, bitter, biting, niveous, cutting, nipping, piercing, pinching, clay-cold, starved, chilled to the bone, shivering, aguish, transi de froid, frostbitten, frost-bound, frost-nipped, cold as a stone, cold as marble, cold as lead, cold as iron, cold as a frog, cold as charity, cold as Christmas, cool as a cucumber, cool as custard, icy, glacial, frosty, freezing, pruinose, wintry, brumal, hibernal, boreal, arctic, Siberian, hyemal, hyperborean, hyperboreal, icebound, frozen out, unwarmed, unthawed, lukewarm, tepid, isocheimal, isocheimenal, isocheimic, frozen, numb, frost-bitten, coldly, bitterly, pierre fendre.