strain1
  
  v.
    - force (a part of one's body or oneself) to make an unusually great effort. 
▸injure (a limb, muscle, or organ) by overexertion.
 ▸make a strenuous and continuous effort.
 - make severe or excessive demands on.
 - pull or push forcibly at something.
 - pour (a mainly liquid substance) through a sieve or similar device to separate out any solid matter. 
▸drain off (liquid) in this way.
 
n.
    - a force tending to strain something to an extreme degree. 
▸Physics  the magnitude of a deformation, equal to the change in the dimension of a deformed object divided by its original dimension.
 - an injury caused by straining a muscle, limb, etc.
 - a severe demand on strength or resources. 
▸a state of tension or exhaustion resulting from this.
 - 
(usu. strains)
 the sound of a piece of music.
 
 
  Derivative
  
  Etymology
  ME: from OFr. estreindre, from L. stringere ‘draw tight’.
 
  
    
strain2
  
  n.
  - a distinct breed, stock, or variety of an animal, plant, or other organism.
 - a tendency in a person's character.
 
 
  Etymology
  OE strīon ‘acquisition, gain’, of Gmc origin.