Final answer:
The abolition of untouchability in the Indian constitution is a social reform that does not pertain to secular characteristics. Secular features typically involve the separation of state and religion, and ensuring no state-sponsored religion, something that the abolition of untouchability doesn't address.
Step-by-step explanation:
The feature of the Indian constitution that does not entail secular characteristics is the abolition of untouchability. Secularism in the context of a constitution typically refers to the separation of religion from the state and ensuring that the government does not favor or promote any particular religion. While the abolition of untouchability is a critical civil rights reform aimed at ending caste-based discrimination, it does not directly relate to the separation of religion and state, or to the state's stance on religion.
On the other hand, provisions like no state religion, cultural and minority rights, and non-discrimination based on social backgrounds contribute to secular characteristics by promoting equality and non-discrimination, including on the basis of religion. No state religion ensures that the state does not officially endorse or establish a particular religion, and cultural and minority rights typically include the protection of religious freedoms, thus supporting secular values.