def del_pos(s):
    """
    Deletes part-of-speech encoding from an entity string, if present.
    :param s: Entity string.
    :return: Entity string with part-of-speech encoding removed.
    """
    if s.endswith("/n") or s.endswith("/a") or s.endswith("/v") or s.endswith("/r"):
        s = s[:-2]
    return s