Large low-temperature specific heat in pyrochlore<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mtext>Bi</mml:mtext></mml:mrow><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mrow><mml:mtext>Ti</mml:mtext></mml:mrow><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mtext>O</mml:mtext><mml:mn>7</mml:mn></mml:msub></mml:mrow></mml:math>

Both amorphous and crystalline materials frequently exhibit low-temperature specific heats in excess of what is predicted using the Debye model. The signature of this excess specific heat is a peak observed in $C/{T}^{3}$ versus $T$. To understand the curious absence of long-range ordering of local distortions in the crystal structure of pyrochlore ${\text{Bi}}_{2}{\text{Ti}}_{2}{\text{O}}_{7}$, we have measured the specific heat of crystalline ${\text{Bi}}_{2}{\text{Ti}}_{2}{\text{O}}_{7}$ and related compounds. We find that the peak in $C/{T}^{3}$ versus $T$ in ${\text{Bi}}_{2}{\text{Ti}}_{2}{\text{O}}_{7}$ falls at a substantially lower temperature than other similar compounds consistent with the presence of disorder. This thermodynamic evidence for disorder in crystalline ${\text{Bi}}_{2}{\text{Ti}}_{2}{\text{O}}_{7}$ is consistent with quenched configurational disorder among Bi lone pairs produced by the geometrical frustration, which could represent a possible realization of ``charge ice.''