| FID | (physics) used as a fixed standard of reference for comparison or measurement |
|---|---|
| FID | relating to or of the nature of a legal trust (i.e. the holding of something in trust for another) |
| FID | a person who holds assets in trust for a beneficiary |
| FID | relating to or of the nature of a legal trust (i.e. the holding of something in trust for another) |
| FID | the legal duty of a fiduciary to act in the best interests of the beneficiary |
| FID | the legal relation that exists when one person justifiably places reliance on another whose aid or protection is sought in some matter |