Where does “photosynthetical” come from?

photosynthetical (English) comes from English photo, from English photography, from French photographie, from Ancient Greek φωτο-, from Ancient Greek φῶς, from Proto-Hellenic pʰáos, from Proto-Indo-European bʰéh₂os, from Proto-Indo-European bʰeh₂-.

Ancestry of “photosynthetical”, step by step

photosynthetical traces back through two separate lines of ancestry.

via English photo

StepLanguageWordMeaning
1EnglishphotoA photograph; A photo finish; To take a...
2EnglishphotographyThe art and technology of producing images on...
3Frenchphotographiephotography; photograph
4Ancient Greekφωτο-
5Ancient GreekφῶςAttic form of φᾰ́ος
6Proto-Hellenicpʰáos
7Proto-Indo-Europeanbʰéh₂os
8Proto-Indo-Europeanbʰeh₂-to shine, glow light; to speak, say
9Proto-Indo-Europeanbʰeh₂-s-ri-

via English synthetical

StepLanguageWordMeaning
1Englishsyntheticalsynthetic
2EnglishsyntheticOf, or relating to synthesis; Produced by...
3Frenchsynthétiquesynthetic
4Ancient Greekσυνθετικόςskilled in putting together, constructive;...
5Ancient Greekσύνθεσιςa putting together, composition, combination,...
6Ancient Greekσυντίθημιto assemble, put together
7Ancient Greekσῠν-together; with, together
8Ancient Greekσύνbeside, with
9Proto-Hellenic*ksúnbeside, with
Every word from Proto-Indo-European bʰeh₂-s-ri-Every word from Proto-Indo-European bʰeh₂-Every word from Ancient Greek φωτο-