Wound, trauma, traumatism, lesion, bruise, contusion are comparable when they mean an injury to one of the organs or parts of the body.
Wound generally denotes an injury that is inflicted by a hard or sharp instrument (as a knife, a bullet, or a club) forcibly driven or applied, and is characterized by breaking of the skin or mucous membrane and usually by damage to the tissues beneath.
In extended use wound can apply to a figurative hurt or blow (as to the mind or to society).
Trauma basically applies to a wound or other injury (as a strain, fracture, or concussion) resulting from external force or violence (as from a fall, a blow, a shot, a stab, or a burn) or from a cause incidental to birth or surgery. Often the term is extended to a mental or emotional blow or stress that results in disordered feelings or behavior or leaves a lasting abnormal impression on the mind.
In this connection trauma tends to pass in meaning from the injury received to the effect it produces.
Traumatism in general use is seldom clearly distinguished from trauma , but in technical use it tends to be applied specifically to the local or general disordered state that results from injury or wounding.
Lesion basically implies an injury or impairment, but in medical use it applies specifically to a usually clearly circumscribed pathological change in tissue that may be caused by a wound or injury or be symptomatic of a disease or degenerative process.
In much of its general use lesion is an extension of the medical sense and implies a damaged or defective point or a weak spot.
Bruise is the general and contusion the more technical term for an injury, ordinarily due to impact, that results in more or less disorganization of tissues beneath the skin without breaking it but with black and blue discoloration due to oozing of blood into the tissues.
Only bruise has appreciable extended use and in this it tends to be strictly metaphoric.