Meaning of SLACK in English


I. ˈslak adjective

( -er/-est )

Etymology: Middle English slak, from Old English sleac; akin to Old Saxon slak slack, Old High German slah, Old Norse slakr slack, Latin laxus slack, loose, spacious, languēre to be languid, Greek lēgein to leave off, stop, Sanskrit laṅga lame

1. : not using due diligence, care, or dispatch : remiss , inattentive , negligent

slack in service


a. : characterized by slowness, sluggishness, or lack of energy : wanting in life, vigor, or strength

a slack pace

a very slack performance

b. : moderate in some quality ; especially : moderately warm

a slack oven

c. : blowing or flowing at low speed — used especially of wind or tide


a. : not tight : not tense or taut : loose , relaxed

a slack rope

b. : lacking in firmness : weak , soft , unsteady

a slack hand

slack control

c. of one edge of a roll of paper : not wound as tightly as the other edge


a. : wanting in activity : not busy : dull

fall is our slack season

b. : marked by a low level of activity : reduced below a desired, normal, or usual level

employment is very slack

5. : lacking in completeness, finish, or perfection

the finish was much slacker than the design


a. : made with joints sufficiently tight for packing dried materials but not watertight

slack cooperage

b. : concerned with or engaged in the making of slack cooperage

Synonyms: see negligent

II. verb

( -ed/-ing/-s )

transitive verb


a. : to be slack, inattentive, or negligent in performing, executing, or completing

slack one's vigilance

b. archaic : to fail to take advantage of (as an opportunity) or use to advantage (as time)

c. : to moderate or slacken deliberately by or as if by relaxing one's energy, zeal, grip, or other controlling factor : cause to lessen (as in speed, vigor, violence, fervor)

slacked his pace as the sun grew hot

— often used with up

slack up one's effort

2. : to cause to be relaxed, loose, or otherwise free from tension : loosen

slack the girth while the horse is cooling

slack a line

— often used with an adverb (as off, out )

slack off the sail


a. : to cause to abate : slake 2

b. : slake 4

intransitive verb


a. : to be or become slack : decline in some effort (as in speed, force, activity) : slow up : relax tension

the wind slacked

b. : to approach an end (as of activity) : cease to progress

our enthusiasm slacked off

retail business slacks down when employment drops

2. : to shirk or evade work or obligations : be or become a slacker, idler, or shirker

3. : slake 3

III. adverb

: slackly

IV. noun

( -s )

Etymology: Middle English slak, from Old Norse slakki

1. dialect England : a pass between hills : glen

2. dialect Britain

a. : a pool of water

b. : marsh

V. noun

( -s )

Etymology: Middle English sleck, probably from Middle Dutch slecke, slacke slag, slack; perhaps akin to Middle Low German slagge slag — more at slag

: the finest screenings of coal produced at a mine and often containing slate and dirt that make it undesirable for fuel unless cleaned — called also coom, culm

VI. noun

( -s )

Etymology: slack (I)

1. : cessation in movement or flow ; specifically : slack water

2. : a part of something that hangs loose without strain

take up the slack of a rope


a. : trousers

b. : long pants for casual wear often of a looser cut than suit trousers and with pleats at the waist — usually used in plural but sometimes sing. in constr.

4. : a lull in activity : a dull season or period

5. : looseness of fit (as of a part in a mechanism) : backlash

6. : the weak or stressless element in a rhythmic unit or foot : unstress

VII. noun

Etymology: probably short for slack jaw

dialect England : impudent talk

VIII. noun

( -s )

Etymology: Middle English slak — more at slake

: slake III

Webster's New International English Dictionary.      Новый международный словарь английского языка Webster.