The melting point of a solid is the temperature at which it changes to liquid state. The melting point of ice
is very close to 273.15 K.
The heat supplied to ice at its melting point is used up by the ice molecules for the change of state process, i.e., the ice molecules uses the heat supplied to break intermolecular attraction so that the ice melts into water. As this heat energy is absorbed by ice without showing any rise in temperature, it is considered that it gets hidden into the contents of the beaker and is known as the latent heat of fusion.
Thus, we can define latent heat of fusion as the amount of heat required to convert a unit mass of a solid into its liquid state, without a change in temperature.
Hope this answers your query,