1.A fold or doubling of a thread, cord, rope, etc., through which another thread, cord, etc., can be passed, or which a hook can be hooked into; an eye, as of metal; a staple; a noose; a bight. "That the probation bear no hinge, nor loop To hang a doubt on."
2.A small, narrow opening; a loophole. "And stop all sight-holes, every loop from whence The eye of Reason may pry in upon us."
3.A curve of any kind in the form of a loop.
4.(Telegraphy) A wire forming part of a main circuit and returning to the point from which it starts.
5.(Acoustics) The portion of a vibrating string, air column, etc., between two nodes; called also ventral segment.
