Slack vs. Lack — What's the Difference?

Not taut or held tightly in position; loose

Deficiency or absence

(of business or trade) characterized by a lack of work or activity; quiet

A particular deficiency or absence

Having or showing laziness or negligence

To be without or in need of

Lewd

To be missing or deficient

(of a tide) neither ebbing nor flowing

To be in need of something

The part of a rope or line which is not held taut; the loose or unused part

A deficiency or need (of something desirable or necessary); an absence, want.

Casual trousers

(obsolete) A defect or failing; moral or spiritual degeneracy.

A spell of inactivity or laziness

(transitive) To be without, to need, to require.

Coal dust or small pieces of coal

(intransitive) To be short (of or for something).

Loosen (something, especially a rope)

To be in want.

Decrease or reduce in intensity, quantity, or speed

(obsolete) To see the deficiency in (someone or something); to find fault with, to malign, reproach.

Work slowly or lazily

Blame; cause of blame; fault; crime; offense.

Slake (lime)

Deficiency; want; need; destitution; failure; as, a lack of sufficient food.

Not tense or taut; loose

To blame; to find fault with.

Lacking in activity; not busy

To be without or destitute of; to want; to need.

Moving slowly; sluggish

To be wanting; often, impersonally, with of, meaning, to be less than, short, not quite, etc.

Lacking in diligence or due care or concern; negligent

To be in want.

Flowing or blowing with little speed

Exclamation of regret or surprise.

(Linguistics) Pronounced with the muscles of the tongue and jaw relatively relaxed; lax.

The state of needing something that is absent or unavailable;

To make looser or less taut

Be without;

To make slower

To be careless or remiss in doing

To slake (lime).

To be or become slack.

To be inactive or avoid work

A loose part, as of a rope or sail

A period of little activity; a lull

A cessation of movement in a current of air or water.

An area of still water.

Unused capacity

Slacks Casual pants that are not part of a suit.

A mixture of coal fragments, coal dust, and dirt that remains after screening coal.

A small dell or hollow.

A bog; a morass.

In a slack manner

(uncountable) The part of anything that hangs loose, having no strain upon it.

(countable) A tidal marsh or shallow that periodically fills and drains.

Unconditional listening attention given by client to patient.

(rail) A temporary speed restriction where track maintenance or engineering work is being carried out at a particular place.

(countable) A valley, or small, shallow dell.

(mining) Small coal; coal dust.

(normally said of a rope) Lax; not tense; not firmly extended.

Weak; not holding fast.

Moderate in some capacity.

Moderately warm.

Moderate in speed.

Lacking diligence or care; not earnest or eager.

Not active or busy, successful, or violent.

Excess; surplus to requirements.

Vulgar; sexually explicit, especially in dancehall music.

(linguistics) Lax.

Slackly.

To slacken.

(obsolete) To mitigate; to reduce the strength of.

To lose cohesion or solidity by a chemical combination with water; to slake.

Small coal; also, coal dust; culm.

A valley, or small, shallow dell.

The part of anything that hangs loose, having no strain upon it; as, the slack of a rope or of a sail.

Lax; not tense; not hard drawn; not firmly extended; as, a slack rope.

Weak; not holding fast; as, a slack hand.

Remiss; backward; not using due diligence or care; not earnest or eager; as, slack in duty or service.

Not violent, rapid, or pressing; slow; moderate; easy; as, business is slack.

Slackly; as, slack dried hops.

To become slack; to be made less tense, firm, or rigid; to decrease in tension; as, a wet cord slackens in dry weather.

To be remiss or backward; to be negligent.

To lose cohesion or solidity by a chemical combination with water; to slake; as, lime slacks.

To abate; to become less violent.

To lose rapidity; to become more slow; as, a current of water slackens.

To languish; to fail; to flag.

To end; to cease; to desist; to slake.

To render slack; to make less tense or firm; as, to slack a rope; to slacken a bandage.

To neglect; to be remiss in.

To deprive of cohesion by combining chemically with water; to slake; as, to slack lime.

To cause to become less eager; to repress; to make slow or less rapid; to retard; as, to slacken pursuit; to slacken industry.

To cause to become less intense; to mitigate; to abate; to ease.

Dust consisting of a mixture of small coal fragments and coal dust and dirt that sifts out when coal is passed over a sieve

A noticeable deterioration in performance or quality;

A stretch of water without current or movement;

The condition of being loose (not taut);

A cord or rope or cable that is hanging loosely;

Avoid responsibilities and work, be idle

Be inattentive to, or neglect;

Release tension on;

Make less active or fast;

Become slow or slower;

Make less active or intense

Become less in amount or intensity;

Cause to heat and crumble by treatment with water;

Not tense or taut;

Lacking in strength or firmness or resilience;

Flowing with little speed as e.g. at the turning of the tide;

Lacking in rigor or strictness;