(1) Penalise (Verb) = subject toa penalty or punishment ; tocause someone a disadvantage;to punish someone for breakinga rule. Legalise (Verb) = make permissibleby law; legitimize ; toallow something by law. Look at the sentences : He was penalised early in thegame for unsportsmanlike conduct. The present tax system penalisespoor people.Same-sex marriages have beenlegalised in many states.