The Collaborative International Dictionary of English v.0.48:

halfpence \half"pence\ (h[=a]"p[e^]ns), n.
   an English coin worth half a penny; -- no longer minted.

   Syn: halfpenny, ha'penny.
        [WordNet 1.5 +PJC] halfpenny

The Collaborative International Dictionary of English v.0.48:

halfpenny \half"pen*ny\, half-penny
\half"-pen*ny\(h[=a]"p[e^]n*n[y^] or h[aum]f"-; 277), n.;pl.
   Half-pence (-pens) or Half-pennies(-p[e^]n*n[i^]z).
   An English coin of the value of half a penny, no longer
   minted; also, the value of half a penny.

   Syn: ha'penny.
        [1913 Webster + WordNet 1.5]