This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
旿 combines 日 (sun) and 午 (noon), but its exact historical development and original meaning are uncertain.
The sun 日 at noon 午 suggests brightness, but the kanji's meaning is unclear. Picture a bright midday sun, but remember the meaning is uncertain.
For ゴ, imagine the sun at noon (午) going strong: go -> ゴ, as the sun goes across the sky.