constrain

Concise Oxford English Dictionary © 2008 Oxford University Press:
constrain/kənˈstreɪn/

▶verb

• 1 compel or force towards a course of action.

  ■ (as adj. constrained) appearing forced.

  ■ severely restrict the scope, extent, or activity of.

• 2 literary imprison.

• 3 archaic bring about by compulsion.

– derivatives
constrainedly adverb.

– origin ME: from OFr. constraindre, from L. constringere ‘bind tightly together’.