Winglet or tip fin
14 CFR § 1.1 — Definitions
Official definition — 14 CFR Part 1
REGULATION — OFFICIAL DEFINITIONWinglet or tip fin means an out-of-plane surface extending from a lifting surface. The surface may or may not have control surfaces.
Reproduced verbatim from the eCFR. Regulatory definitions control how the term is used throughout 14 CFR.
Is this a regulation?
Yes — this is regulatory text and is legally binding.
Definition published in 14 CFR Part 1. Regulatory definitions are legally binding wherever the defined term is used in 14 CFR.