ETYM Latin perturbare, perturbatum; per + turbare to disturb, from turba a disorder: cf. Old Fren. perturber. Related to Per-, and Turbid.
1. To throw into great confusion or disorder; SYN. derange, throw out of kilter.
2. To disturb in mind or make uneasy or cause to be worried or alarmed; SYN. unhinge, disquiet, trouble, cark, distract, disorder.
3. To disturb or interfere with the usual path of an electron or atom.
4. To cause a celestial body to deviate from a theoretically regular orbital motion, esp. as a result of interposed or extraordinary gravitational pull.