1.
behavior, manner, attitude
The outward behavior or demeanor that reveals or conceals one's true feelings or intentions.
2.
sign, indication, hint
A subtle sign or indication of something, especially an attitude or feeling that shows through one's behavior.
Pronunciation
素振り (behavior/sign) vs. 素振り (practice swing in sports) — same kanji, different readings and meanings. This entry covers the そぶり reading.
Key expression
何食わぬ素振り — "an innocent look," acting as if one knows nothing or has done nothing wrong. This is one of the most common uses.