These words are different ways of indicating what is permitted, allowable, countenanced or sanctioned by custom or by some recognized authority.

Lawful implies conformity with laws, statutes, canons, precepts, principles, rules, etc. intended to regulate the conduct of those coming within their particular field of action. Thus one speaks of lawful debts, a lawful claim, a lawful marriage, of conducting a lawful business or making a lawful decision. Legal has nearly the same meaning, but is restricted chiefly to statute laws as they apply at certain times and places or under prescribed conditions.

• Divorce is lawful but subject to various legal requirements before taking final effect; the legal speed limit within the city is 35 miles per hour.

Constitutional refers tot he fundamental laws and principles that have been formally adopted to govern the efficient operations of a state acting as a unit towards those subject to its control, and in its dealings with other states.

• He stood on his constitutional rights; proposed constitutional amendments of the type that cannot become law until approved by a majority of electors voting at a referendum.

Strict usage distinguishes constitutional from all the other terms because of its direct reference to a document, instrument or body of rules acknowledged as paramount in determining what is lawful or legal : an appeal dismissed on constitutional grounds.

Legitimate originally meant whatever was declared to be lawful : a legitimate child; a legitimate owner of the land. It is now very generally applied to anything that is recognized by custom or in popular usage as conforming to established rules or standards, being regular, orderly or acceptable in form, style, etc.: legitimate theatre; a legitimate conclusion; legitimate procedures. Licit is the adjective form in English of the Latin verb licet , it is permitted. It is seldom used nowadays, and then in the sense of something strictly lawful : a licit marriage; licit traffic in drugs or liquor. From the same root we get our licence, licentiate and licentious, as well as the far better known and more widely used negative form illicit .