Source : Webster's Revised Unabridged Dictionary (1913)

Fat \Fat\, n.
   1. (Physiol. Chem.) An oily liquid or greasy substance making
      up the main bulk of the adipose tissue of animals, and
      widely distributed in the seeds of plants. See {Adipose
      tissue}, under {Adipose}.

   Note: Animal fats are composed mainly of three distinct fats,
         tristearin, tripalmitin, and triolein, mixed in varying
         proportions. As olein is liquid at ordinary
         temperatures, while the other two fats are solid, it
         follows that the consistency or hardness of fats
         depends upon the relative proportion of the three
         individual fats. During the life of an animal, the fat
         is mainly in a liquid state in the fat cells, owing to
         the solubility of the two solid fats in the more liquid
         olein at the body temperature. Chemically, fats are
         composed of fatty acid, as stearic, palmitic, oleic,
         etc., united with glyceryl. In butter fat, olein and
         palmitin predominate, mixed with another fat
         characteristic of butter, butyrin. In the vegetable
         kingdom many other fats or glycerides are to be found,
         as myristin from nutmegs, a glyceride of lauric acid in
         the fat of the bay tree, etc.

   2. The best or richest productions; the best part; as, to
      live on the fat of the land.

   3. (Typog.) Work. containing much blank, or its equivalent,
      and, therefore, profitable to the compositor.

   {Fat acid}. (Chem.) See {Sebacic acid}, under {Sebacic}.

   {Fat series}, {Fatty series} (Chem.), the series of the
      paraffine hydrocarbons and their derivatives; the marsh
      gas or methane series.

   {Natural fats} (Chem.), the group of oily substances of
      natural occurrence, as butter, lard, tallow, etc., as
      distinguished from certain fatlike substance of artificial
      production, as paraffin. Most natural fats are essentially
      mixtures of triglycerides of fatty acids.

Fat \Fat\, n. [See {Vat}, n.]
   1. A large tub, cistern, or vessel; a vat. [Obs.]

            The fats shall overflow with wine and oil. --Joel
                                                  ii. 24.

   2. A measure of quantity, differing for different
      commodities. [Obs.] --Hebert.

Fat \Fat\, a. [Compar. {Fatter}; superl. {Fattest}.] [AS.
   f[=ae]tt; akin to D. vet, G. fett, feist, Icel. feitr, Sw.
   fet, Dan. fed, and perh. to Gr. pi^dax spring, fountain,
   pidy`ein to gush forth, pi`wn fat, Skr. pi to swell.]
   1. Abounding with fat; as:
      (a) Fleshy; characterized by fatness; plump; corpulent;
          not lean; as, a fat man; a fat ox.
      (b) Oily; greasy; unctuous; rich; -- said of food.

   2. Exhibiting the qualities of a fat animal; coarse; heavy;
      gross; dull; stupid.

            Making our western wits fat and mean. --Emerson.

            Make the heart of this people fat.    --Is. vi. 10.

   3. Fertile; productive; as, a fat soil; a fat pasture.

   4. Rich; producing a large income; desirable; as, a fat
      benefice; a fat office; a fat job.

            Now parson of Troston, a fat living in Suffolk.
                                                  --Carlyle.

   5. Abounding in riches; affluent; fortunate. [Obs.]

            Persons grown fat and wealthy by long impostures.
                                                  --Swift.

   6. (Typog.) Of a character which enables the compositor to
      make large wages; -- said of matter containing blank,
      cuts, or many leads, etc.; as, a fat take; a fat page.

   {Fat lute}, a mixture of pipe clay and oil for filling
      joints.

Fat \Fat\, v. t. [imp. & p. p. {Fatted}; p. pr. & vb. n.
   {atting}.] [OE. fatten, AS. f[=ae]ttian. See {Fat}, a., and
   cf. {Fatten}.]
   To make fat; to fatten; to make plump and fleshy with
   abundant food; as, to fat fowls or sheep.

         We fat all creatures else to fat us.     --Shak.

Fat \Fat\, v. i.
   To grow fat, plump, and fleshy.

         An old ox fats as well, and is as good, as a young one.
                                                  --Mortimer.

Source : WordNet®

fat
     n 1: a soft greasy substance occurring in organic tissue and
          consisting of a mixture of lipids (mostly
          triglycerides); "pizza has too much fat"
     2: a kind of body tissue containing stored fat that serves as a
        source of energy; adipose tissue also cushions and
        insulates vital organs; "fatty tissue protected them from
        the severe cold" [syn: {adipose tissue}, {fatty tissue}]
     3: excess bodily weight; "she found fatness disgusting in
        herself as well as in others" [syn: {fatness}, {blubber},
        {avoirdupois}] [ant: {leanness}]
     [also: {fatting}, {fatted}, {fattest}, {fatter}]

fat
     v : make fat or plump; "We will plump out that poor starving
         child" [syn: {fatten}, {flesh out}, {fill out}, {plump},
         {plump out}, {fatten out}, {fatten up}]
     [also: {fatting}, {fatted}, {fattest}, {fatter}]

fat
     adj 1: having much flesh (especially fat); "he hadn't remembered
            how fat she was" [ant: {thin}]
     2: having a relatively large diameter; "a fat rope"
     3: containing or composed of fat; "fatty food"; "fat tissue"
        [syn: {fatty}] [ant: {nonfat}]
     4: lucrative; "a juicy contract"; "a nice fat job" [syn: {juicy}]
     5: marked by great fruitfulness; "fertile farmland"; "a fat
        land"; "a productive vineyard"; "rich soil" [syn: {fertile},
         {productive}, {rich}]
     6: a chubby body; "the boy had a rounded face and fat cheeks"
        [syn: {rounded}]
     [also: {fatting}, {fatted}, {fattest}, {fatter}]

Source : Free On-Line Dictionary of Computing

FAT
     
        {File Allocation Table}