Silky means smooth and slippery like fine woven thread. Silky hair, a silky texture, silky smooth.
It praises smoothness with a slight slipperiness — silky is what shampoo advertisements promise and what a good sauce has. Applied to a voice or a manner it means smooth in a way that may not be trustworthy: a silky operator. Note silken, which is more literary; and that silk itself came to Europe along the trade route that took its name from the cloth.
1adjectivesilkySmooth and slippery like fine woven thread.
“The cat's fur felt silky under my hand.”
2adjectivemannerSmooth in a manner that may not be trustworthy.
“The salesman's silky voice made me trust him less, not more.”
silky is a quality of smoothness.
Middle English sylky is silk plus -y. Silk came into English from a Slavic or Baltic route rather than through Latin, which is unusual for a trade word.
Middle English
sylky
English, today
silky
From Middle English sylky, equivalent to silk + -y.
Etymology from Wiktionary, CC BY-SA