From Liquipedia Dota 2 Wiki

Silence is a status effect that prevents the affected unit from casting spells. Silence will also stop any channeling spells that the enemy is currently using. Silence does not affect items and passive abilities.

In addition to the list here, hexes also silence their target.

Silence Abilities[edit]

Hero Abilities
Hero Ability
Bloodseeker Blood Rite
Death Prophet Silence
Disruptor Static Storm
Doom Doom
Drow Ranger Gust
Earth Spirit Geomagnetic Grip
Enigma Black Hole
Night Stalker Crippling Fear
Puck Waning Rift
Riki Smoke Screen
Silencer Last Word
Global Silence
Skywrath Mage Ancient Seal
Item Abilities
Item Ability
Scythe of Vyse Hex
Orchid Malevolence Soul Burn
Bloodthorn Soul Rend

See also[edit]