slack
     adj 1: not tense or taut; "the old man's skin hung loose and gray";
            "slack and wrinkled skin"; "slack sails"; "a slack
            rope" [syn: {loose}]
     2: lacking in strength or firmness or resilience; "flaccid
        muscles"; "took his lax hand in hers"; "gave a limp
        handshake"; "a limp gesture as if waving away all desire
        to know" G.K.Chesterton; "a slack grip" [syn: {flaccid}, {lax},
         {limp}]
     3: flowing with little speed as e.g. at the turning of the
        tide; "slack water"
     4: lacking in rigor or strictness; "such lax and slipshod ways
        are no longer acceptable"; "lax in attending classes";
        "slack in maintaining discipline" [syn: {lax}]
     n 1: dust consisting of a mixture of small coal fragments and
          coal dust and dirt that sifts out when coal is passed
          over a sieve
     2: a noticeable deterioration in performance or quality; "the
        team went into a slump"; "a gradual slack in output"; "a
        drop-off in attendance"; "a falloff in quality" [syn: {slump},
         {drop-off}, {falloff}, {falling off}]
     3: a stretch of water without current or movement; "suddenly
        they were in slack water"
     4: the condition of being loose (not taut); "he hadn't counted
        on the slackness of the rope" [syn: {slackness}]
     5: a cord or rope or cable that is hanging loosely; "he took up
        the slack"
     v 1: avoid responsibilities and work, be idle
     2: be inattentive to, or neglect; "He slacks his attention"
     3: release tension on; "slack the rope"
     4: make less active or fast; "He slackened his pace as he got
        tired"; "Don't relax your efforts now" [syn: {slacken}, {slack
        up}, {relax}]
     5: become slow or slower; "Production slowed" [syn: {slow}, {slow
        down}, {slow up}, {slacken}]
     6: make less active or intense [syn: {slake}, {abate}]
     7: become less in amount or intensity; "The storm abated"; "The
        rain let up after a few hours" [syn: {abate}, {let up}, {slack
        off}, {die away}]
     8: cause to heat and crumble by treatment with water; "slack
        lime" [syn: {slake}]
Source: WordNet® 2.0

slack n. 1. Space allocated to a disk file but not actually used to
   store useful information. The techspeak equivalent is `internal
   fragmentation'. Antonym: {hole}. 2. In the theology of the {Church of
   the SubGenius}, a mystical substance or quality that is the prerequisite
   of all human happiness.

   Since Unix files are stored compactly, except for the unavoidable
   wastage in the last block or fragment, it might be said that "Unix has
   no slack". See {ha ha only serious}.


Source: The Jargon File