"Reachiest" is a comparative adjective form of "reaching." In IPA phonetic transcription, it is spelled as /ˈriːtʃiəst/. The first syllable "ree" is pronounced with a long "e" sound, followed by "ch" pronounced as "tʃ." The second syllable "i" is pronounced with a short "i" sound, and the third syllable "est" is pronounced as "ist." The word "reachiest" is used to describe something or someone that reaches the highest or furthest point.