def merge_definitions(def_list):
    """Merge definitions if they are exactly equivalent or contained within each other

    Args:
        def_list (List[str]): potentially distinct definitions for same term

    Returns:
        List[str]: List of unique definitions for term
    """
    for a_idx, a in enumerate(def_list):
        for b_idx, b in enumerate(def_list):
            a_low = a.lower()
            b_low = b.lower()
            if a_idx == b_idx:
                # Don't compare the same index
                continue
            if a_low == b_low: 
                def_list.remove(b)
                continue
            if a_low in b_low:
                def_list.remove(a)
            if b_low in a_low: 
                def_list.remove(b)

    return def_list