Meaning of formal in English
1. following the customary forms; suitable for official or important occasions
a formal dress
a formal call
2. strictly conventional or stiffly ceremonious in manner; rigidly formal
The party was extremely formal.
Everyone at the party there was terribly formal.
She is formal about table manners.
You needn't be so formal with me.
3. made or done officially; officially recognized; official
a formal agreement
a formal complaint
a formal declaration of war
4. given officially at a school, college etc.
a formal education[training, qualification, ...]
5. commonly used in official situations, not in conversation
formal language[words]