adjective

weak

WEEK/wiːk/

Having little strength, intensity, or effective power.

The weak man struggles to lift even a light dumbbell.

An older man struggles to lift a very light dumbbell, making his lack of physical strength visible through disproportionate effort.

Etymology

Old Norse veikr already meant lacking strength. English extended this idea beyond bodily weakness to things that lack force or effectiveness, such as tools and medicines.

In context

Libertarianism.org39:49

instead of great energies guided by vigorous reason and strong feelings strongly controlled by a conscientious will its result is weak feelings and weak energies

2. "Of individuality, as one of the elements of well-being." | Individualism: A Reader

More examples

My legs feel weak after the long hike.
The radio signal is weak inside the tunnel.
That argument is too weak to convince the committee.
Too much water makes the coffee weak.

Forms

weak · weaker · weakest

weakness noun — The condition of lacking strength or power.

weakly adverb — With little strength, force, or effectiveness.

Similar words

frail: Emphasizes physical delicacy and vulnerability to injury or strain.
faint: Describes low intensity that makes something difficult to perceive.
ineffective: Emphasizes failure to produce results rather than limited strength.