1.  lawful(a = adj.all) - conformable to or allowed by law; "lawful methods of dissent"
Antonym: unlawful
Derived form noun lawfulness₁

2.  lawful(s = adj.all) rule-governed - according to custom or rule or natural law;

3.  lawful(s = adj.all) rightful, true - having a legally established claim; "the legitimate heir"; "the true and lawful king"
Derived form noun lawfulness₁

4.  lawful(s = adj.all) legitimate, licit - authorized, sanctioned by, or in accordance with law; "a legitimate government"
Derived form noun lawfulness₁

1.  Conformable to law; allowed by law; legitimate; competent. [1913 Webster]

2.  Constituted or authorized by law; rightful; as, the lawful owner of lands. [1913 Webster]
" In some of the States, and for some purposes, a woman attains lawful age at eighteen. Abbott."

lawful, adj. conforming with, permitted by, or recognized by law; not illegal or (of a child) illegitimate.

Derivative:
lawfully adv. lawfulness n.

N  permission, leave, allowance, sufferance, tolerance, toleration, liberty, law, license, concession, grace, indulgence, favor, dispensation, exemption, release, connivance, vouchsafement, authorization, warranty, accordance, admission, permit, warrant, brevet, precept, sanction, authority, firman, hukm, pass, passport, furlough, license, carte blanche, ticket of leave, grant, charter, patent, letters patent, permitting, permissive, indulgent, permitted, patent, chartered, permissible, allowable, lawful, legitimate, legal, legalized, licit, unforbid, unforbidden, unconditional, by leave, with leave, on leave, speciali gratia, under favor of, pace, ad libitum, by all means, yes, avec permissin, brevet d'invention.

N  legality, legitimacy, legitimateness, legislature, law, code, corpus juris, constitution, pandect, charter, enactment, statute, rule, canon, ordinance, institution, regulation, bylaw, byelaw, decree, ordonnance, standing order, plebiscite, legal process, form, formula, formality, rite, arm of the law, habeas corpus, fieri facias, jurisprudence, nomology, legislation, codification, equity, common law, lex, lex nonscripta, law of nations, droit des gens, international law, jus gentium, jus civile, civil law, canon law, crown law, criminal law, statute law, ecclesiastical law, administrative law, lex mercatoria, constitutionalism, constitutionality, justice, court, tribunal, judge, lawyer, attorney, legal counsel, legal, legitimate, according to law, vested, constitutional, chartered, legalized, lawful, statutable, statutory, legislatorial, legislative, regulatory, regulated, legally, in the eye of the law, de jure, ignorantia legis neminem excusat, ignorance of the law is no excuse, where law ends tyranny begins.

N  due, dueness, right, privilege, prerogative, prescription, title, claim, pretension, demand, birthright, immunity, license, liberty, franchise, vested interest, vested right, sanction, authority, warranty, charter, warrant, constitution, tenure, bond, claimant, appellant, plaintiff, having a right to, entitled to, claiming, deserving, meriting, worthy of, privileged, allowed, sanctioned, warranted, authorized, ordained, prescribed, constitutional, chartered, enfranchised, prescriptive, presumptive, absolute, indefeasible, unalienable, inalienable, imprescriptible, inviolable, unimpeachable, unchallenged, sacrosanct, due to, merited, deserved, condign, richly deserved, allowable, lawful, licit, legitimate, legal, legalized, square, unexceptionable, right, equitable, due, en r gle, fit, fitting, correct, proper, meet, befitting, becoming, seemly, decorous, creditable, up to the mark, right as a trivet, just the thing, quite the thing, selon les r gles, duly, ex officio, de jure, by right, by divine right, jure divino, Dei gratia, in the name of, civis Romanus sum, +a chaque saint sa chandelle.