The Collaborative International Dictionary of English v.0.48:

Suckle \Suc"kle\, v. i.
   To nurse; to suck. [R.]
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Suckle \Suc"kle\, n.
   A teat. [Obs.] --Sir T. Herbert.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Suckle \Suc"kle\, v. t. [imp. & p. p. Suckled; p. pr. & vb. n.
   Suckling.] [Freq. of suck.]
   To give suck to; to nurse at the breast. --Addison.
   [1913 Webster]

         The breasts of Hecuba
         When she did suckle Hector, looked not lovelier.
                                                  --Shak.
   [1913 Webster]

         They are not weak, suckled by Wisdom.    --Landor.
   [1913 Webster]

WordNet (r) 3.0 (2006):

suckle
    v 1: suck milk from the mother's breasts; "the infant was
         suckling happily"
    2: give suck to; "The wetnurse suckled the infant"; "You cannot
       nurse your baby in public in some places" [syn: breastfeed,
       suckle, suck, nurse, wet-nurse, lactate, give
       suck] [ant: bottlefeed]

Moby Thesaurus II by Grady Ward, 1.0:

62 Moby Thesaurus words for "suckle":
   aliment, aspirate, bib, booze, breast-feed, breathe in, care for,
   cherish, coddle, cosset, cradle, cultivate, drain the cup, draw in,
   drink, drink in, drink off, drink to, drink up, dry-nurse, fatten,
   fatten up, feed, fondle, force-feed, foster, guzzle, imbibe,
   inhale, inspire, lactate, lavish care on, mother, nourish, nurse,
   nurture, nutrify, pamper, pledge, pull, quaff, sip, slurp, sniff,
   sniffle, snuff, snuff in, snuffle, spoon-feed, stuff, suck,
   suck in, sup, sustain, swig, swill, tipple, toast, toss down,
   toss off, wash down, wet-nurse