adj.
 (primmer, primmest)
 feeling or showing disapproval of anything improper; stiffly correct.
v.
 (prims, primming, primmed)
 purse (the mouth or lips) into a prim expression.
Derivative
  
  Etymology
  C17 (as v.): prob. ult. from OFr. prin, Provençal prim ‘excellent, delicate’, from L. primus ‘first’.