constraint

(kən-strāntˈ)

1. The threat or use of force to prevent, restrict, or dictate the action or thought of others.
2. The state of being restricted or confined within prescribed bounds: soon tired of the constraint of military life.
3. One that restricts, limits, or regulates; a check: ignored all moral constraints in his pursuit of success.
4. Embarrassed reserve or reticence; awkwardness: “All constraint had vanished between the two, and they began to talk” (Edith Wharton).