once
Just one time
Once is a busy function word whose meanings arise mainly from the closely related word one.
The adverb conveys one time (I went there once) or formerly: They visited the ruins of the once magnificent castle.
At once conveys immediacy or concurrence: I can’t do two things at once.
Once is used to join clauses to show one thing immediately follows, and may depend upon, another: Once you light the fuse, get out of there.
In the past
- previouslyBefore the present moment
- erstwhilePreviously but not now
- onetimeFormerly but not now
- ex-Prefix meaning former
bygone · past · earlier · prior · before · sometime · quondam
Conditional clause marker
Brief period of time
- instantBriefest unit of time
- flashBrief burst of light
- secondUnit smaller than minute
- glimpseFleeting view
fleeting · transient · ephemeral · passing · momentary · temporary · short-lived · quick
Likelihood of occurrence
- occasionNotable event or moment
- somedayVague future time
- eventuallyAt a later time
- finallyAt the end
One in number
- soleFoot's bottom surface
- solitaryExisting alone, apart
- loneExisting by itself
- isolatedSeparated from others
individual · unrepeatable · nonrecurring · exclusive · just · merely · solely
Before the present
- yesteryearTime not long past
- historicallyIn past times
- remembranceAct of holding something in mind
- nostalgiaLonging for the past
Without any pause
- immediatelyWithout any pause
- directlyWithout intermediary steps
- straightawayWithout pause or hesitation
- promptlyWithout hesitation or delay
forthwith · now · quickly · simultaneously · together
formerly
In the past
- previouslyBefore the present moment
- erstwhilePreviously but not now
- onetimeFormerly but not now
ex- · bygone · past · earlier · prior · before · sometime · quondam
if
Conditional clause marker
moment
Brief period of time
glimpse · fleeting · transient · ephemeral · passing · momentary · temporary · short-lived · quick · briefly
chance
Likelihood of occurrence
- occasionNotable event or moment
- somedayVague future time
- eventuallyAt a later time
single
One in number
isolated · individual · unrepeatable · nonrecurring · exclusive · just · merely · solely
ago
Before the present
- yesteryearTime not long past
- historicallyIn past times
- remembranceAct of holding something in mind
instantly
Without any pause
- immediatelyWithout any pause
- directlyWithout intermediary steps
- straightawayWithout pause or hesitation
promptly · forthwith · now · quickly · simultaneously · together
- once upon a timeTraditional narrative opening
- at onceWithout any delay
- once in a whileAt irregular intervals
- for onceAs an exception
- once moreRepeated another time
- once and for allFinally and permanently