The Collaborative International Dictionary of English v.0.48:

Suffocate \Suf"fo*cate\, a. [L. suffocatus, p. p. of suffocare
   to choke; sub under + fauces the throat. Cf. Faucal.]
   Suffocated; choked. --Shak.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Suffocate \Suf"fo*cate\, v. t. [imp. & p. p. Suffocated; p.
   pr. & vb. n. Suffocating.]
   1. To choke or kill by stopping respiration; to stifle; to
      smother.
      [1913 Webster]

            Let not hemp his windpipe suffocate.  --Shak.
      [1913 Webster]

   2. To destroy; to extinguish; as, to suffocate fire.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Suffocate \Suf"fo*cate\, v. i.
   To become choked, stifled, or smothered. "A swelling
   discontent is apt to suffocate and strangle without passage."
   --collier.
   [1913 Webster]

WordNet (r) 3.0 (2006):

suffocate
    v 1: deprive of oxygen and prevent from breathing; "Othello
         smothered Desdemona with a pillow"; "The child suffocated
         herself with a plastic bag that the parents had left on the
         floor" [syn: smother, asphyxiate, suffocate]
    2: impair the respiration of or obstruct the air passage of;
       "The foul air was slowly suffocating the children" [syn:
       suffocate, stifle, asphyxiate, choke]
    3: become stultified, suppressed, or stifled; "He is suffocating
       --living at home with his aged parents in the small village"
       [syn: suffocate, choke]
    4: suppress the development, creativity, or imagination of; "His
       job suffocated him" [syn: suffocate, choke]
    5: be asphyxiated; die from lack of oxygen; "The child
       suffocated under the pillow" [syn: suffocate, stifle,
       asphyxiate]
    6: feel uncomfortable for lack of fresh air; "The room was hot
       and stuffy and we were suffocating"
    7: struggle for breath; have insufficient oxygen intake; "he
       swallowed a fishbone and gagged" [syn: gag, choke,
       strangle, suffocate]