(anatomy) lumen (cavity within tubular organ)

inside, within (physical location) / between, among / while, during, inside or within a span of time / (when used possessively) one's own, my, our

sooner or later / eventually / before long

flow, run, rush, stream / wash away / (for rumors, news, etc. to) circulate, go around / (for time to) pass / (for music or video to) play / fail, fall through / trend

The Inner Path; a term derived from the Sanskrit referring to any orthodox Buddhist doctrine which "treads the inner path" to enlightenment.

(formal) blood

cavity / chamber / hollow

road / path / way / route / course

blood type

coelenteron