Synonyms for Passing:

adj.

brief, casual (adjective)
evanescent, transitory, ephemeral, short-lived, slight, superficial, fleeting, impermanent, fugacious, temporary, transient, momentary, cursory.
fugacious (adjective)
fugacious.
human (adjective)
mortal.
moving (adjective)
flowing, coursing, going, active, moving, transiting, running, proceeding, stirring.
transient (adjective)
evanescent, impermanent, momentary, short-term, fickle, temporary, cursory, instantaneous, rootless, volatile, restless, transitory, Flitting, shifting, transient, flickering, fleeting, ephemeral, fading, mortal, temporal, brief, mutable, changeable, short-lived.

n.

closure, conclusion, withdrawal, close, finish, crossing, completion. fleet, inconstant, continue, variable, time, floating. downwind, eastbound, homeward, around, ahead, counterclockwise, clockwise, down, cross country, left. little, few, mere, barely, minimum, sparse, scant, only, slight. death rate, morbidity, bereavement, death throes, mortality, death toll. slip by, intervene, wear on, elapse, go by, time flies, tick away, creep by, the passage of time. pending, sketchy, superficial, incomplete, abortive, outstanding, light touch, partial, unfinished, undone. act (noun)
passing play, passing game, pass, passage.
death (noun)
decease, fatality, end, dissolution, annihilation, release, extinction, death, expiration, demise, quietus, loss, ending, parting, finish, cessation.
event (noun)
passage.
passing (noun)
exceedingly, transient, casual, temporary, qualifying, departure, release, impermanent, perfunctory, moving, passage, short-lived, expiration, pass, fugacious, loss, transitory, ephemeral, passing play, exit, careless, passing game, cursory, extremely, satisfactory, going, overtaking.
travel (noun)
passage.

v.

dying (verb)
Deceasing, Perishing, Succumbing, dying, departing, falling, expiring, Ceasing, passing on, passing away.
happening (verb)
happening, Occurring, ensuing, taking place, coming to pass, transpiring.
moving (verb)
actuating, Budging, relocating, shifting, Transferring.

Other synonyms:

withdrawal, tick away, little, closure, elapse, close, floating, finish, inconstant, death throes, completion, creep by, conclusion, slip by. variable, wear on. fleet, intervene. go by. Other relevant words:
continue, minimum, conclusion, around, left, careless, casual, light touch, mere, passing game, departure, exceedingly, down, variable, loss, slight, bereavement, time, passage, mortality, sparse, intervene, ahead, qualifying, close, withdrawal, abortive, perfunctory, clockwise, counterclockwise, morbidity, unfinished, extremely, crossing, eastbound, superficial, homeward, overtaking, only, incomplete, exit, passing play, floating, scant, completion, pass, elapse, finish, barely, satisfactory, outstanding, inconstant, partial, few, downwind, sketchy, little, undone, fugacious, fleet, pending, closure.

Usage examples for passing

  1. Olcott was passing and he stopped beside them. – For the Allinson Honor by Harold Bindloss
  2. And passing Grimshaw without a glance he went upstairs. – O. Henry Memorial Award Prize Stories of 1921 by Various