formal Definition

1. Relating to or involving etiquette, ceremony or conventional procedure generally.

Example: formal dress
Thesaurus: conventional, traditional, orthodox, approved, received, correct.
2. Stiffly polite rather than relaxed and friendly.

Thesaurus: impersonal, stiff, rigid, polite, prim, perfunctory.
3. Valid; official; explicit.

Example: a formal agreement
Example: formal proof
Thesaurus: official, confirmed, directed, bureaucratic, legal.
4. Said of language: strictly correct with regard to grammar, style and choice of words, as distinct from conversational.
5. Organized and methodical.

Example: the formal approach to teaching
6. Precise and symmetrical in design.

Example: a formal garden
7. Relating to outward form as distinct from content.

In a formal way.