'Weaker' in the Bible

Now there was long war between the house of Saul and the house of David: and David waxed stronger and stronger, but the house of Saul waxed weaker and weaker.

Ye husbands, in like manner, dwell with your wives according to knowledge, giving honor unto the woman, as unto the weaker vessel, as being also joint-heirs of the grace of life; to the end that your prayers be not hindered.