allowed by law► legal something that is legal is allowed by law: · This trade in foreign currency is perfectly legal.become legal: · Divorce finally became legal in 1992.· Over 3,000 gay couples have married since it became legal for them to do so last year. legal tender (=forms of money that are legally accepted): · In Maastricht, Dutch Guilders, Deutschmarks and Belgian Francs are all considered legal tender.
► lawful formal actions or methods that are lawful are allowed by law, especially as compared with actions or methods that are not legal: · Protesters must only use lawful methods of opposing the government.it is lawful to do something: · It is lawful to employ someone under the age of sixteen if their parents agree.· The FBI will use all reasonable and lawful means to gather intelligence information.· 'Do you take this woman to be your lawful wedded wife?' intoned the priest. 'I do,' murmured Carlos.
► legitimate legitimate activities, organizations, or claims are done or work according to, normal laws and rules: · He is a criminal who runs a legitimate business as well.· Tobacco smuggling into the UK is seriously affecting the profits of legitimate importers.· How can I be sure that an on-line business is legitimate?· At least three of the dead woman's relatives have a legitimate claim to her house.· The government has refused to recognise the far-right group as a legitimate political party.
► above board an activity or a way of doing business that is above board is done legally, even if it may seem slightly dishonest: · He assured us that the insurance claim was honest and above board, but I'm not so sure.· I'm sure Peggy wouldn't let anything happen that wasn't perfectly open and above board.
► within the law: act/keep/stay/remain/operate within the law to make sure that what you do is legal: · He makes tough business deals, but he makes sure he always stays within the law.· Security forces must not only act within the law, but must be seen to do so.· Building contractors must operate within the law by ensuring that an acceptable standard of work is carried out.
► legality formal whether something is legal or not: the legality of something: · The European Court will decide on the legality of his claim.· The union immediately challenged the legality of the decision.be of dubious/questionable/uncertain legality (=when it is not clear whether something is legal or not): · The Appeal Court judge said that his conviction was of dubious legality.· This was the first of several actions that were of questionable legality, and which eventually led to his resignation.
honest and legal: 
His plans for opening a coffee shop are completely above board.