The Tocharian B word yäp-
Word yäp-
j ə p
IPA jəp
Meaning sunset

Comments
Douglas Q. Adams, “Etymological Dictionary of Tocharian B”, 1999, Brill

Other words that might be of interest
kauṃ ‘sun’, pūwar ‘fire’, taur ‘ash, dust’, läkutsetstse ‘bright’, pälk- ‘burn’, pälśalñe ‘burning’, wärs-2 ‘darken’, sleme ‘flame’, tsāk ‘illuminate’, parkāsaṃ ‘illumination’, korośāna ‘bright yellow’, skiyo ‘shade, shadow’, pälk ‘shine’