रिष्

रिषँ = र इ ष चंद्र बिंदी
sharp object pointed surface
sharp object pointed inside
blooddy pointed inside
bloody surface

commentary
If we consider रि to be a remnant of ऋ, the meaning is -
ऋषं = ऋ ष चंद्र बिंदी
superior pointed inside
superior pointed surface
superior pointed outside/periphery
superior pointted pull
superior pointed push
superior needle point objectified (इ as स्वर विभक्ति)

commentary
As superior (ऋ) + abstract(objectify-इ(needle point-ष)), ऋषि means someone who is superior and goes first into unknown and to whom others follow like a thread. This, of course, is later day interpretation when abstraction abilities evolved.
Pre-abstraction era meaning would have been more like (superior pointed outside), akin to a leader with better weapons leading the group.