Impact vs Harmful - What's the difference?

impact | harmful |

As a noun impact

is the striking of one body against another; collision.

As a verb impact

is to compress; to compact; to press or pack together.

As an adjective harmful is

of a kind likely to be damaging; injurious.




(en noun)
  • The striking of one body against another; collision.
  • The force or energy of a collision of two objects.
  • The hatchet cut the wood on impact .
  • (chiefly, medicine) A forced impinging.
  • His spine had an impingement; L4 and L5 made impact , which caused numbness in his leg.
  • A significant or strong influence; an effect.
  • His friend's opinion had an impact on his decision.
    Our choice of concrete will have a tremendous impact on the building's mechanical performance.

    Usage notes

    * Adjectives often applied to "impact": social, political, physical, positive, negative, good, bad, beneficial, harmful, significant, great, important, strong, big, small, real, huge, likely, actual, potential, devastating, disastrous, true, primary. * The adposition generally used with "impact" is "on" (such as in last example in section above) * There are English speakers who are so ). In defensive editing, the solution is to replace the figurative noun sense with effect'' and the verb sense with ''affect , which nearly always produces an acceptable result. (Rarely, a phrase such as "the impact of late effects" is better stetted to avoid "the effect of [...] effects".)

    Derived terms

    * impactful * impactive * impact statement * Western impact


    (en verb)
  • To compress; to compact; to press or pack together.
  • If fecal incontinence is caused by impacted stool in the rectum, the impaction must be removed.
  • (proscribed) To influence; to affect; to have an on.
  • ''I can make the changes, but it will impact the schedule.
  • To collide or strike.
  • When the hammer impacts the nail, it bends.

    Usage notes

    Some authorities object to the verb sense of impact'', meaning "to influence; to affect; to have an impact on" or "to collide or strike". Although most .

    Derived terms

    * impactor



    Alternative forms

    * harmfull (archaic)


  • of a kind likely to be damaging; injurious
  • Wear a hat to protect your skin from harmful sunlight.

    Usage notes

    * Nouns to which "harmful" is often applied: effect, consequence, impact, influence, emission, chemical, ingredient, substance, gas, agent, additive, drug, radiation, dust, organism, plant, animal, insect, action, act, behavior, component, content, activity, interference, use.


    * injurious; see also


    * beneficial * harmless

    See also

    * harm