Definition from Wiktionary, the free dictionary
thence (not comparable)
- From there, from that place or from that time.
- I came thence.
- (technical) Commonly used in property descriptions by land surveyors, or aviators relating to IFR established flying procedures
- Cross fix at 6000 feet, thence descend to 3000 feet and fly direct to MAP (missed approach point).
- (literary) Deriving from this or as a result of this.