upon
On top of
Upon is an old preposition that is now largely replaced by on.
It can still be used instead of on to bring an air of formality, or when two syllables rather than one are required in poetry or lyrics.
Upon survives in many fixed phrases and quotations because of this: When you wish upon a star…
On the summit of
- restingIn a state of stillness
- perchedResting in place
- mountedFixed in position
- sittingBeing in seated posture
positioned · lying · overlying · placed · set · laid · supported · balanced
Without any pause
- instantlyWithout any pause
- forthwithWithout delay
- whereuponAfter which something happened
- thereuponImmediately following that
once · moment · arrival · occurrence · happening · onset · commencement
Lose footing momentarily
discover · find · meet · run · light · hit · encounter · serendipity
atop
On the summit of
sitting · positioned · lying · overlying · placed · set · laid · supported · balanced · propped
immediately
Without any pause
thereupon · once · moment · arrival · occurrence · happening · onset · commencement
rely
Trust for support
hinge · rest · contingent · predicated · based · conditional · incumbent
stumble
Lose footing momentarily
fall · discover · find · meet · run · light · hit · encounter · serendipity
heaped
Piled in abundance
row · successive · repeated · compounded · multiplied
verge
Border or cusp